I admit, this is a long read, but there is a lot to be passionate about nuclear energy.
(and I still couldn’t cover it all)
I would argue that the more time you spend learning about nuclear energy, the more amazing it becomes and the more passion you feel about it. In short, I see it as the only real solution we have for fighting climate change, but in addition to that, it will also save the human race and bring the world up to a standard of living never seen before – without massive trade-offs to the environment. The trade-offs are not zero, but they are by far the best we have.Currently, we are working with nuclear reactors that were designed several decades ago. In spite of that, they are very good, but amazingly inefficient. However, since nuclear energy is about 1 million+ times more dense than chemical energy, it means you can power your house on about 4 pencil eraser sized chunks of ceramic (made from Uranium oxide, enriched). The chemical way of doing this requires literally TONS of coal. The weight of those 4 uranium oxide chunks? About an ounce (it is dense stuff).
People love to complain “what about the waste“? I suggest that even our current trade-offs are pretty reasonable. “Spent” fuel when it comes out of the reactor is highly radioactive (I’ll tell you why later, it is very interesting). After about 10 years, most of the radioactivity is gone, but it is still radioactive enough it should be kept out of accidental contact with the environment on a long term basis. Even so, we are literally talking about ceramic pellets inside metal tubes, it is not like it is some kind of goo you see in bad movies.
The total waste from 50 years of nuclear power supplying 20% of US power, is about 70,000 tons. That translates to 1 football field stacked 10 ft high. Not much. However, about 94% is U238, which could be used as fuel in other reactors, about 1% is remaining U235 and another 1% or so is plutonium (mostly Pu239), both of these which also could be used as fuel in other reactors.
The current “light water” reactors used in the US just don’t bother harvesting this extra energy. Uranium is so cheap and the energy so dense, that it makes more sense economically to mine more uranium and put the “waste” away. The funny thing is though, we only use about 1% of the energy from uranium with the current design, but it still kicks butt over chemical burning.
Thanks to xkcd.com for showing properly how nuclear power compares with burning things.
But that only scratches the surface. The reactors we use today are solid fueled, and cooled with water. There are many, many other designs, that are being researched and developed for commercial use. Solid fueled reactors can’t consume all the energy in the fuel in one step, it requires reprocessing to get at more of the locked up energy. France and several other countries do this, but either way, you wind up with materials trapped in the uranium and these interfere with operation.
Newer designs propose a liquid fueled medium, you dissolve the uranium (and in some cases, thorium) into a fluoride or other salt, and melt it. Now that the fuel is liquid, things simply separate by density. You can skim off the fission products and store them and perhaps even access valuable medical isotopes. You also can easily add new fuel by dropping in more to melt. Doing this drastically increases your fuel to waste ratio, roughly 99+% of the fuel is consumed since you always can remove reaction products and add more fuel. These are known as “Molten Salt Reactors”.
Thorium is another amazing thing. Th232 is the natural isotope, and it can not fission on its own. It is known as “fertile” not “fissile” fuel. If it absorbs a neutron (such as in a molten salt reactor above), you can “breed” it to Th233, which then decays to U233, and U233 is fissile. One more neutron unlocks the energy in U233, which gives out at least 2 more neutrons, and the cycle continues. Why is this amazing? Because for one, Th232 is 400x more common than the U235 we consume in reactors today, and requires no enrichment.
Introductory video about thorium and MSRs
Reactors in the US today require that we take natural uranium (about 0.7% U235) and do isotopic separation (an energy intensive process, but still worth it by far), to bring it up to about 3-5% U235. You need about 90%+ for a bomb, which is one of many reasons a nuclear reactor can’t be a nuclear bomb. The result of that enrichment is “waste” (depleted) uranium, and enriched uranium which is (partly) used in the reactor.
Thorium requires no such enrichment – hit it with a neutron, and separate out the U233 chemically to run your reactor. This molten salt reactor using thorium is called a “LFTR” or “Liquid Fluoride Thorium Reactor” and is one of many designs currently being worked on around the world today, though most are starting with uranium first.
Thorium has another interesting advantage – it rarely makes Plutonium when put in a reactor, and when it does, it makes Pu238 first (not Pu239). You can separate out Pu238, and it is NOT fissile, so it is not a bomb material. However, perhaps you have heard of an “RTG”? An RTG is a radioisotope thermal generator. We need them to explore space much past mars. All of our probes that went past mars have one, as does the current mars rover. It produces electricity purely from the decay heat of Pu238 decaying into other isotopes. Since the radiation from Pu238 is known (alpha) and easily shielded, space exploration MUST have this substance to any real hope of exploration in the future. LFTRs would make this material.
Thorium becoming U233 also has value beyond that of power. U233 decays into very special isotopes that are needed for various industries, and one is being considered for cancer research. This is no ordinary research. Picture a radioisotope bonded to an antibody designed to attach to cancer cells. It is injected, arrives at the cancer site, attaches, and blasts just those few local cells to kill them. This kind of treatment could work on “impossible” cancers of today like pancreatic and Leukemia. Idaho national labs (INL) was working on this, though they have been quiet as of late.
Molten salt reactors run safer too – if there is a leak or other catastrophic event, the fuel simply drains into a tank and solidifies. The shape of the tank prevents further nuclear activity and it simply cools. Every accident with a nuclear plant that released material into the environment was a failure of not enough cooling (getting to the reactors in time). Fukushima could have been prevented by opening up the reactors to the ocean, as it would have cooled them, but they didn’t want to damage the reactors with salt water.
Molten salt and many other designs are also designed to run hotter than current reactors, which means more thermal efficiency. It also means the “waste” heat (Tcold) can be about 100 deg C, which means you can desalinate seawater from the waste heat. What would THAT mean to the world?
The higher temperatures would allow us to generate chemical reactions that we now have to burn coal or gas to accomplish. Many things would be in reach, such as making ammonia from water and nitrogen in the air. We currently consume over 1% of the country’s energy making ammonia for fertilizer for food and industrial use, that energy is done by fossil.
Watch the entire “Aim High” video, highly recommended. See also other work from Robert Hargraves on this topic in his books.We use container ships to move things across the ocean, and regulations allow them to burn incredibly dirty “bunker fuel” oil. This adds the equivalent pollution of millions of cars, all from a few ships. We could make them nuclear based, eliminating that pollution and probably doubling their speed too.
With reactor fuel now even cheaper than we have now, and the reactors costing less since they can be built smaller, our cost of electric power would drop, far below what we pay now. What would THAT do to the economy? What would you spend roughly 5-20% of your extra money on? Which – many things would be cheaper since…
We could make our own liquid fuels. You COULD actually burn ammonia for fuel, though it is about 1/3rd the output of gasoline, but we could make plenty of other liquid fuels, removing CO2 from seawater, and the hydrogen from seawater to generate it. It requires lots of energy, but with nuclear, particularly “Gen IV” (including molten salt reactors) you HAVE lots of power, so we could convert the liquid fuel use of the world to a closed cycle. Now you get the energy density and portability of liquid fuels (needed for air travel especially) in a closed cycle. No more CO2 build-up, no need to drill more wells.
When you use thorium this efficiently, the numbers are staggering. The math works out such that: If you dug a hole in some average place on earth, and then extracted the thorium to put into a reactor (MSR) and got all the energy out, the energy equivalent would be like filling that hole where you took out the dirt to the brim with OIL… 30x over. There would be no sense in drilling for oil anymore.
Every nuclear plant, even with our current technology, saves millions of lives. By not having to burn coal to compensate for the energy we need, people don’t die from mining that extra coal, processing it, shipping it, and then getting more diseases from the particulate. Coal plants release far more radiation than nuclear plants).
Nuclear energy has the lowest deaths per kWh than any energy source we currently use, and I’m including wind and solar. And, I’m including Chernobyl and Fukushima. Contrary to what people claim (we can discuss that later), the total deaths from Chernobyl were under 100, and Fukushima was 0. However, the tsunami and suicides from being uprooted killed about 20,000.
People also think we don’t need nuclear sometimes because we have wind and solar. I did the math, if you replaced just Palo Verde, you’d need about 100 sq miles of solar panels just on a kWh basis. Worse still, output would be 0 at night, near zero on cloudy days, and 3x too much during the peak. It is not reliable power, so you have to back it up. Your options are: nuclear with no backup needed, coal with no backup needed, “green” with added burning of natural gas as “backup” (most plants rely HEAVILY on natural gas). As Germany rapidly discovered, as you shut down nukes, you burn more coal. There is very little you can do about it because nothing else has the power density or stability of these.
These are most of the reasons I’m passionate about nuclear, but there are just so many other possibilities. How about indoor farms for vegetation? Cheap electricity means we could grow food in climate controlled, LED lit conditions, with no harmful insects, and thus less chemical use and waste run-off. It would increase the output of a farm vs its land area many-fold as you could now have what amounts to a skyscraper producing food. Even a single story would be better though, since fully controlled conditions would more than double yield and cut usage of other chemicals in half.
Going even more sci-fi, since the MSR/LFTR plants are so efficient, and require basically no intervention, why not build them as “robots” (self-running plants). Use the energy generated to make more of them with energy to spare, and now you have a self-replicating system of power plants. Your energy cost is now basically 0, since no humans are needed, and all the energy required (which would be your major cost) is made by the plants.
Remember the RTG’s on space probes? If you really want to explore space, or possibly colonize it, you need nuclear, and a lot more than a few RTGs. That probably means MSRs, since they are efficient and power dense.
I am convinced that the world does not need to starve itself on a thin gruel of expensive energy, but instead to embrace and develop newer and cheaper nuclear technologies, gaining access to more and more energy. This energy is what we need to live on and enjoy this planet for all of the billions of people and the billions more that we would be easily able to afford.
Knowing all this, how could you NOT be passionate about nuclear?