Is Nuclear Energy Green?

Is Nuclear Energy Green?

Is Nuclear Energy Green?

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Correction to what I say at 17 mins 29 seconds: It’s 3 meters in diameter and 20 meters tall (not 3 meters in diameter and 20 feet tall). Sorry about that!

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Is nuclear power good or bad? In this much-asked-for episode I will summarize the most up-to-date numbers on the status of nuclear power and break down it’s pros and cons. We will also look at what the new technological developments have to offer: molten salt reactors, thorium reactors, and small modular reactors. I learned a low while working on this video and I hope you find this summary useful.

The table which I show at 3 minutes 16 seconds is from this IPCC report https://www.ipcc.ch/site/assets/uploa…

The paper from Muellner et al which I discuss at 6 minutes 43 seconds is here:
https://www.sciencedirect.com/science…

The figure which I show at 7 mins 22 seconds is from the World Nuclear Energy Status Report that you can read here:
https://www.worldnuclearreport.org/IM…

The 2013 paper I mention at 8 minutes 51 seconds is this:
https://pubs.acs.org/doi/abs/10.1021/…

The 2016 paper about the death toll of nuclear versus renewables that I mention at 9 minutes 22 seconds is here:
https://www.sciencedirect.com/science…

The WHO/Chernobyl Forum estimate for the death toll from the Chernobyl accident is from this report:
https://inis.iaea.org/collection/NCLC…

The quote I show at 14 minutes 36 is from this report:
https://www.iaea.org/publications/135…
(sorry for the weird audio quality there)

The Nature article about the thorium reactor in China which I show at 15 minutes 28 seconds is this:
https://www.nature.com/articles/d4158…

And finally, the Science news piece I mention at 17 mins 46 seconds is this:https://www.science.org/content/artic…

Many thanks to Jordi Busqué for helping with this video http://jordibusque.com/

0:00 Intro
2:30 Climate Friendly
6:04 Not Renewable
7:05 Expensive
8:22 Dangerous
12:13 Fast Breeders
13:42 Molten Salt Reactors
14:22 Thorium Reactors
15:43 Small Modular Reactors
18:00 Summary
21:12 Sponsor Message

#science #technology #nuclear #climate


Content

0.179 -> A lot of people have asked me to do a video about nuclear power.
4.24 -> But that turned out to be really difficult.
7.479 -> You won’t be surprised to hear that opinions about nuclear power are extremely polarized
12.62 -> and every source seems to have an agenda to push.
16.02 -> Will nuclear power help us save the environment and ourselves, or is it too dangerous and
21.369 -> too expensive?
22.65 -> Do thorium reactors or the small modular ones change the outlook?
27.86 -> Is nuclear power green?
29.36 -> That’s what we’ll talk about today.
36.63 -> I want to do this video a little differently so you know where I’m coming from.
40.45 -> I’ll first tell you what I thought about nuclear power before I began working on this
44.82 -> video.
46.21 -> Then we’ll look at the numbers, and in the end, I’ll tell you if I’ve changed my
50.81 -> mind.
51.81 -> When the accident in Chernobyl happened I was 9 years old.
54.55 -> I didn’t know anything about nuclear power or radioactivity.
58.54 -> But I was really scared because I saw that the adults were scared.
62.53 -> We were just told, you can’t see it but it’ll kill you.
66.67 -> Later, when I understood that this had been an unnecessary scare, I was somewhat pissed
71.44 -> off at adults in general and my teachers in particular.
75 -> Yes, radioactive pollution is dangerous, but in contrast to pretty much any other type
80.33 -> of pollution it’s easy to measure.
83.18 -> That doesn’t make it go away but at least we know if it’s there.
87.71 -> Today, I worry much more about pollution from the chemical industry which you won’t find
92.71 -> unless you know exactly what you’re looking for and also have a complete chemistry lab
96.95 -> in the basement.
98.76 -> And I worry about climate change.
100.63 -> So, I’ve been in favor of nuclear power as a replacement for fossil fuels since I
105.88 -> was in high school.
107.18 -> In 2008, I over-optimistically predicted the return of nuclear power.
112.95 -> Then of course in 2011, the Fukushima accident happened, after which the German government
118.71 -> decided to phase out nuclear power, but continued digging up coal, buying gas from Russia, and
124.58 -> importing nuclear power from France.
128.78 -> However, in all fairness I haven’t looked at the numbers for more than 20 years.
135.749 -> So that’s what we’ll do next, and then we’ll talk again later.
140.349 -> Fossil fuels presently make up almost two thirds of global electric power production.
146.239 -> Hydropower makes up about 16 percent, and all other renewables together about 10 percent.
152.769 -> Power from nuclear fission makes up the rest, also about 10 percent.
157.919 -> Nuclear power is “green” in the sense that it doesn’t directly produce carbon
162.409 -> dioxide.
163.76 -> I say “directly” because even though the clouds coming out of nuclear power plants
169.37 -> are only water vapor, power plants don’t grow on trees.
173.879 -> They have to be built from something by someone, and the materials, their transport, and the
180.12 -> construction itself have a carbon footprint.
183.419 -> But then, so does pretty much everything else.
186.019 -> I mean, even breathing has a carbon footprint.
189.379 -> So one really has to look at those numbers in comparison.
192.909 -> A good comparison comes from the 2014 IPCC report.
197.719 -> This table summarizes several dozens of studies with a minimum, maximum, and median value.
203.709 -> All the following numbers are in grams of carbon dioxide per kilowatt hour and they
208.151 -> are average values for the entire lifecycle of those technologies, so including the production.
215.44 -> For coal, the median that the IPCC quotes is 820, gas is a bit lower with 490, solar
222.559 -> is a factor 10 lower than gas, with about 40.
226.56 -> Wind is even better than solar with a median of about 11.
229.9 -> And the median for nuclear is 12 grams per kiloWatthour, so comparable to that of wind,
236.529 -> but there is a huge gap to the maximum value which according to some sources is as high
241.819 -> as 110, so about twice as high as solar.
246.019 -> An estimate that’s a little bit higher than even the highest value the IPCC quotes comes
251.39 -> from the World Information Service on Energy, WISE, which is based in the Netherlands.
257.23 -> They calculated that nuclear plants produce 117 grams of carbon dioxide per kilowatt-hour.
263.94 -> It’s not entirely irrelevant to mention that the mission of WISE is to “fight nuclear”
270.199 -> according to their own website.
271.699 -> That doesn’t make their number wrong, but they clearly have an agenda and may not be
277.62 -> the most reliable source.
279.419 -> But these estimates differ not so much because someone is stupid or lying, at least not always,
286.3 -> but because there is some uncertainty in these numbers that affect the outcome.
290.539 -> That’s things like the quality of uranium resources, how far they need to be transported,
296.83 -> different methods of mining or fuel production, and their technological progress, and so on.
302.43 -> In the scientific literature, the value that is typically used is somewhat higher than
307.21 -> the IPCC median, about 60-70 grams of carbon dioxide per kilo Watthour.
312.99 -> And the numbers for renewables should also be taken with a grain of salt because they
318.49 -> need to come with energy storage which will also have a carbon footprint.
323.61 -> I think the message we can take away here is that either way you look at it, the carbon
329 -> footprint of nuclear power is dramatically lower than that of fossil fuels, and roughly
334.439 -> comparable to some renewables, exact numbers are hard to come by.
339.699 -> So that’s one thing nuclear has going in its favor: it has a small carbon footprint.
345.27 -> Another advantage is that compared to wind and solar, it doesn’t require much space.
350.72 -> Nuclear power is therefore also “green” in the sense that it doesn’t get in the
355.28 -> way of forests or agriculture.
357.889 -> And yet another advantage is that it generates power on demand, and not just when the wind
362.96 -> blows or the sun shines.
364.99 -> Let us then talk about what is maybe the biggest disadvantage of nuclear power.
369.629 -> It’s not renewable.
372.11 -> The vast majority of nuclear power plants which are currently in operation work with
376.319 -> Uranium 235.
379.129 -> At the moment, we use about 60 thousand tons per year.
383.13 -> The world resources are estimated to be about 8 million tons.
387.62 -> This means if we were to increase nuclear power production by a factor of ten, then
393.259 -> within 15 to 20 years uranium mining would become too expensive to make economic sense.
400.11 -> This was pretty much the conclusion of a paper that was published a few months ago by a group
404.56 -> of researchers from Austria.
406.629 -> They estimate that optimistically nuclear power from uranium-235 would save about 2
413.56 -> percent of global carbon dioxide emissions by 2040.
417.599 -> That’s not nothing, but it isn’t going to fix climate change – there just isn’t
423.139 -> enough uranium on this planet.
425.909 -> The second big problem with nuclear power is that it’s expensive.
430.18 -> A medium sized nuclear power plant currently costs about 5-10 billion US dollars, though
436.139 -> large ones can cost up to 20 billion.
439.569 -> Have a look at this figure is from the World Nuclear Energy Status report 2021 (page 293).
444.81 -> It shows what’s called the levelized cost of energy in US dollar per megawatt hour,
450.129 -> that’s basically how much it costs to produce power over the entire lifetime of some technology,
456.3 -> so not just the running cost but including the production.
461.31 -> As you can see, nuclear is the most expensive.
464.36 -> It’s even more expensive than coal, and at the moment roughly 5 times more expensive
469.93 -> than solar or wind.
471.939 -> If the current trend continues, the gap is going to get even wider.
476.749 -> On top of this comes that insurance for nuclear power plants is mandatory, the premium is
481.819 -> high, and those expenses from the plant owners go on top of the electricity price.
487.509 -> So at the moment nuclear power just doesn’t make a lot of economic sense.
492.4 -> Of course this might change with new technologies, but before we get to those we have to talk
497.689 -> about the biggest problem that nuclear power has.
501.069 -> People are afraid of it.
503.529 -> Accidents in nuclear power plants are a nightmare because radioactive contamination can make
507.949 -> regions uninhabitable for decades, and tragic accidents like Chernobyl and Fukushima have
514.44 -> arguably been bad publicity.
517.779 -> However, the data say that nuclear power has historically been much safer than fossil fuels,
523.94 -> it’s just that the death toll from fossil fuels is less visible.
530.149 -> In 2013, researchers from the NASA Goddard Institute for Space Studies and Columbia University
535.01 -> calculated the fatalities caused by coal, gas and nuclear, and summarized their findings
541.279 -> in units of Deaths per TeraWatthour.
545.13 -> They found that coal kills more than a hundred times more people than nuclear power, the
549.871 -> vast majority by air pollution.
552.149 -> They also calculate that since the world began using nuclear power instead of coal and gas,
557.26 -> nuclear power has prevented more than 1.8 million deaths.
560.279 -> Another study in 2016 found a death rate for nuclear that was even lower, about a factor
568.13 -> 5 less.
569.13 -> The authors of this paper also compared the risk of nuclear to hydro and wind and found
574.1 -> that these renewables actually have a slightly higher death rate, though in terms of economic
580.22 -> damage, nuclear is far worse.
583.19 -> I am guessing now you all want to know just how exactly people die from renewables.
588.829 -> Well, since you ask.
591.81 -> For wind it’s stuff like “a bus collided with a truck transporting a turbine tower”
597.05 -> or an air-craft crashed into a wind turbine, or workers falling off the platform of an
602.259 -> offshore windfarm.
603.97 -> For solar, it’s accidents in manufacturing sites, electric shocks from improper wiring,
608.839 -> or falls from roofs.
611.269 -> The number for hydropower is dominated by a single accident when a dam broke in China
616.16 -> in 1975.
618.31 -> The water flooded several villages and killed more than 170 thousand people.
624.019 -> The Chernobyl accident, in comparison, killed less than 40 people directly.
629.25 -> The World Health Organ-ization estimates long-term deaths from cancer as a consequence of the
634.079 -> Chernobyl accident to be 4000-9000.
638.56 -> There is a group of researchers which claims it’s at least a factor 10 higher but this
643.759 -> claim has remained highly controversial.
646.699 -> The number of direct fatalities from the Fukushima accident is zero.
651.839 -> One worker died 7 years later from lung cancer, almost certainly a consequence of radiation
656.56 -> exposure.
658.04 -> About 500 died from the evacuation, mostly elderly and ill people whose care was interrupted.
664.79 -> And this number is unlikely to change much in the long run.
669.11 -> According to the WHO, the radiation exposure of the Fukushima accident was low except for
675.17 -> the direct vicinity of the power plant which was evacuated.
679.3 -> They do not expect the cancer risk for the general population to significantly rise.
684.93 -> The tsunami which caused the accident to begin with killed considerably more people, at least
690.48 -> 15 thousand.
692.329 -> I don’t want to trivialize accidents in the nuclear industry, of course they are tragic.
698.019 -> But there’s no doubt that they pale in comparison to fossil fuels, which cause pollution that,
703.89 -> according to some estimates kills as much as a million people per year.
708.49 -> Also, fun fact, coal contains traces of radioactive minerals that are released when you burn it.
715.61 -> Indeed, radioactivity levels are typically *higher* near coal plants than near nuclear
720.889 -> power plants.
721.889 -> Again, you see, there are some differences in the details but pretty much everyone who
727.06 -> has ever seriously looked at the numbers agrees that nuclear is one of the safest power sources
732.769 -> we know of.
733.769 -> Okay, so we have seen that the biggest two disadvantages of nuclear power are that it’s
739.76 -> not renewable and that it’s expensive.
743.089 -> But this is for the conventional nuclear power plants that use uranium 235 which is only
749.19 -> 0 point 7 percent of all uranium we find on Earth.
753.66 -> Another option is to use fast breeder reactors which work with the other 99 point 3 percent
759.49 -> of uranium on earth, that’s the isotope uranium-238.
764.569 -> A fast breeder transmutes uranium-238 to plutonium-239, which can then be used as reactor fuel like
773.199 -> uranium-235.
775.449 -> And this process continues running with the neutrons that are produced in the reaction
780.11 -> itself, so the reactor “breeds” its own fuel, hence the name
785.97 -> Fast breeders are not new; they have been used here and there since the 1940’s.
791.07 -> But they turned out to be expensive, unreliable, and troublesome.
795.339 -> The major problems are that they are cooled with sodium which is very reactive, and they
800.73 -> also can’t be shut down as quickly as the conventional nuclear power plants.
805.18 -> To make a long story short, they didn’t catch on, and I don’t think they ever will.
810.76 -> But technology in the nuclear industry has much advanced in the past decades.
815.519 -> The most important innovations are molten salt reactors, thorium reactors, and small
820.99 -> modular reactors.
823.12 -> Molten salt reactors work by mixing the fuel into some type of molten salt.
827.93 -> The big benefit of doing this is that it’s much safer.
830.98 -> That’s partly because molten salt reactors operate at lower pressure, but mostly because
835.97 -> the reaction has a “negative temperature coefficient”.
839.259 -> That’s a complicated way of saying that the energy-production slows down when the
844.019 -> reactor overheats, so you don’t get a runaway effect.
848.649 -> Molten salt reactors have their own problems though.
851.81 -> The biggest one is that the molten salt fuel is highly corrosive and quickly degrades the
857.019 -> material meant to contain it.
859.519 -> How much of a problem this is in practice is currently unclear.
863.79 -> Molten salt reactors can be run with a number of different fuels, one of them is thorium.
870.509 -> Thorium is about 4 times more abundant than uranium, however, fewer resources are known,
878.66 -> so in practice this isn't going to make a big difference in the short run.
883.17 -> The real advantage is that these reactors can use essentially the entire thorium, not
888.67 -> just a small fraction of it, as is the case with the normal uranium reactors.
894.07 -> This means, thorium reactors produce more energy from the same amount of fuel and, as
899.131 -> a consequence, thorium could last for thousands of years.
903.829 -> Thorium is also a waste product of the rare-earth mining industry, so trying to put it to use
908.98 -> is a good idea.
910.49 -> However, the problem is still that the technology is expensive.
915.18 -> There is currently only one molten salt thorium reactor in operation, and that’s in China.
920.96 -> It started operating in September 2021.
923.73 -> It’s just a test facility that will generate only 2 Megawatt, but if they are happy with
930.139 -> the test the Chinese have plans for a bigger reactor with 373 Megawatt for the next decade,
936.509 -> though that is still fairly small for a power plant.
939.95 -> It’ll be very interesting to see what comes out of this.
943.66 -> And the biggest hope of the nuclear industry is currently small modular reactors.
948.73 -> The idea is that instead of building big and expensive power plants, you build reactors
953.66 -> that are small enough to be transported.
956.709 -> Mass-producing them in a factory could bring down the cost dramatically.
961.67 -> A conventional plant generates typically a few Gigawatt in electric energy.
966.42 -> The small modular reactors are comparable in size to a small house, and have an energy
971.31 -> output of some tens of Megawatt.
974.31 -> For comparison, that’s about ten times as much as a wind turbine on a good day.
980.22 -> That they are modular means they are designed to work together so one can build up power
985.649 -> plants gradually to the desired capacity.
989.12 -> Several projects for small modular reactors are at an advanced stage in the USA, Russia,
994.17 -> China, Canada, the UK, and South Korea.
997.98 -> Most of the current projects use uranium as fuel, partly in the molten salt design.
1003.73 -> But the big question is, will the economics work out in the end?
1007.97 -> This isn’t at all clear, because making the reactors smaller may make them cheaper
1012.87 -> to manufacture, but they’ll also produce less energy during their lifetime.
1018.209 -> Certainly at this early stage, small modular reactors aren’t any cheaper than big ones.
1024.15 -> A cautious example comes from the American company NuScale.
1028.03 -> They sit in Utah and have been in business since 2007.
1032.4 -> They were planning to build twelve small reactors with 60 MegaWatt by 2027.
1038.44 -> Except for being small they are basically conventional reactors that work with enriched
1043.02 -> Uranium.
1044.02 -> Each of those of those reactors is a big cylinder, about 3 meters in diameter and 20 meters tall.
1049.65 -> Their original cost estimate was about 4.2 billion dollars.
1053.68 -> However, last year they announced that had to revise their estimate to $6.2 billion and
1060.18 -> said they’d need three years longer.
1062.93 -> In terms of cost per energy that’s even more expensive than conventional nuclear power
1068.28 -> plants.
1069.36 -> The project is subsidized by the department of energy with 1.4 billion, but several funders
1075.71 -> backed out after the announcement that the cost had significantly increased.
1080.39 -> Ok, so that concludes my rundown of the numbers.
1083.72 -> Let’s see what we’ve learned.
1086.65 -> What speaks in favor of nuclear energy is that it’s climate friendly, has a small
1090.97 -> land use, and creates power on demand.
1094.48 -> What speaks against it is that it’s expensive and ultimately not renewable.
1099.7 -> The disadvantages could be alleviated with new technologies, but it’s unclear whether
1104.94 -> that will work, and even if it works, it almost certainly won’t have a significant impact
1110.41 -> on climate change in the next 20 years.
1113.51 -> It also speaks against nuclear power that people are afraid of it.
1118.03 -> Even if these fears are not rational that doesn’t mean they don’t exist.
1122.28 -> If someone isn’t comfortable near a nuclear power plant, that affects their quality of
1126.83 -> life, and that can’t just be dismissed.
1130.07 -> There are two points I didn’t discuss which you may have expected me to mention.
1134.82 -> One is nuclear proliferation and the risk posed by nuclear power plants during war times.
1140.72 -> This is certainly an important factor, but it’s more political than scientific, and
1145.46 -> that would be an entirely different discussion.
1148.2 -> The other point I didn’t mention is nuclear waste.
1151.15 -> That’s because I think it’s a red herring which some activist groups are using in the
1156.121 -> attempt to scare people.
1157.71 -> For what I am concerned, burying the stuff in a safe place solves the problem just fine.
1163.27 -> It’s right that there aren’t any final disposal sites at the moment, but Finland
1168.63 -> is expected to open one next year and several other countries will follow.
1173.58 -> And no, provided adequate safety standards, I wouldn’t have a problem with a nuclear
1179.24 -> waste deposit in my vicinity.
1181.68 -> So, what did I learn from this.
1185.11 -> I learned that nuclear power has become economically even more unappealing than it already was
1191.16 -> 20 years ago, and it’s not clear this will ever change.
1195.47 -> Personally I would say that this development can be left to the market.
1199.68 -> I am not in favor of regulation that makes it even more difficult for us to reduce carbon
1204.49 -> emission, to me this just seems insane.
1208.71 -> In all fairness it looks like nuclear won’t help much, but then again, every little bit
1214.53 -> helps.
1215.53 -> Having said that, I think part of the reason the topic is so controversial is that what
1221.64 -> you think is the best strategy depends on local conditions.
1226.08 -> There is no globally “right” decision.
1229.46 -> If your country has abundant solar and wind power, it might not make sense to invest in
1235.27 -> nuclear.
1236.27 -> Though you might want to keep in mind that climate change can affect wind and precipitation
1241.19 -> patterns in the long run.
1243.21 -> If your country is at a high risk of earthquakes, then maybe nuclear power just poses too high
1249.55 -> a risk.
1251.19 -> If on the other hand renewables are unreliable in your region of the world, you don’t have
1256.901 -> a lot of space, and basically never see earthquakes, nuclear power might make a lot of sense.
1264.33 -> In the end I am afraid my answer to the question “Is nuclear power green?” is “It’s
1271.48 -> complicated.”
1272.48 -> This video was sponsored by Brilliant.
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1283.51 -> It’s not that I think it’s unimportant, it just didn’t stick.
1287.11 -> So don’t feel bad if you can’t remember how nuclear reactors work.
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1357.51 -> Thanks for watching, see you next week.

Source: https://www.youtube.com/watch?v=0kahih8RT1k