where we last left off, running an industrial economy requires a source of cheap and stable electricity. Electricity provided by wind and solar is intermittent and therefore does not fit the bill. Electricity from coal, diesel and natural gas does work but causes environmental damage, plus these fossil fuels are mostly past peak, are increasingly expensive to produce, and won’t last for much longer in any case. Hydroelectric is a good choice, but all the sweet spots for it have already been tapped. Boutique resources such as biomass, micro-hydro, tidal energy and what have you are insufficient to power an industrial economy. This leaves nuclear energy, but nuclear energy has some major problems.
Thus, there are no good solutions, but this may not be a problem because, you see, without a stable source of cheap electricity there won’t be an industrial economy, and without an industrial economy there will be neither supply of nor demand for any of the above. There will still be demand for firewood, to be met by you wandering up and down a stretch of abandoned highway collecting dry tree branches for your campfire, on which to cook some rodents you caught with a forked stick.
If you find this scenario unappealing and wish to look for other options, there is little choice but to look more closely at nuclear energy. Yes, it has some major problems, but what if these problems have solutions? You haven’t thought of that, have you? But that’s not as outlandish an idea as you might imagine. Huge teams of brilliant scientists and engineers working diligently for decades do sometimes come up with solutions to even the most difficult problems. Clearly, it would be foolish to simply assume that all major problems will be solved, but I believe that it does make sense to try to stay informed about the actual progress that has been made, if only to satisfy your intellectual curiosity, should you have any.
Before we go any further, let me assure you that I don’t have any particular political stance vis-à-vis nuclear energy. I have not flipped from being anti-nuke to being pro-nuke or any such thing. Furthermore, let me state unequivocally that your own political opinion on the desirability or undesirability of nuclear power matters not in the slightest. In fact, if ever I let on that it matters at all, feel free to assume that I’ve gone senile and to come over and shoot me, because I don’t want to be a burden. In turn, if I catch you signing anti-nuke petitions, going to anti-nuke rallies or otherwise making your opinion on the matter known, I will assume the same about you, although I won’t bother to come over and shoot you. My wish is to inform, not to influence. If, armed with this knowledge, you find ways to avoid having to cook rodents on a stick (by figuring out where in the world there will still be power and moving there while there is still time) I will be happy for you.
With these preliminaries out of the way, let me rattle off some key facts about nuclear power that you should definitely have under your hat in order to understand the importance of what’s to follow. Nuclear energy is quite unlike chemical energy in that it is something like 100000 times more powerful: 1kg of nuclear fuel provides as much energy as 100 tonnes of coal. Naturally occurring uranium contains two uranium isotopes: U-235 and U-238. Only U-235 is directly capable of sustaining a fission reaction: when a U-235 atom is hit with a neutron, it fissions into Barium-141 and Krypton-92, which are very short-lived and decay into other elements, liberating much energy along the way. It also emits 3 neutrons, which can then hit other U-235 atoms, sustaining the chain reaction.
Only 0.7% of naturally occurring uranium is the useful isotope U-235, the rest is the (almost) useless isotope U-238. Since 0.7% is nowhere near enough to sustain a chain reaction, a complicated process is used to “enrich” uranium, raising the U-235 concentration to between 3% and 5% (nowhere near enough to make a bomb, by the way) by separating out some of the excess U-238. This is done by converting uranium dioxide, (UO2, also called yellowcake) into uranium hexafluoride (UF6) which is a colorless solid that evaporates at slightly above room temperature. The UF6 gas is then fed into a cascade of centrifuges that separate out the isotopes. The enriched mixture is then converted back into UO2 which is formed into pellets that make up nuclear fuel. This is all based on very complicated, sensitive technology which only a handful of countries have.
The reason U-238 is almost useless rather than completely useless is that under certain conditions it can capture a neutron and turn into Plutonium-239, which is just as useful as U-235 in sustaining a chain reaction. Spent nuclear fuel, in which a large percentage of U-235 has been burned out, contains some amount of Pu-239, which can then be reprocessed into mixed oxide (MOX) fuel. It is important to note that plutonium produced by nuclear power plants is useless for making nuclear bombs because the fractions of isotopes are wrong: weapons-grade stuff can’t have too much Pu-240, which is unstable, but the plutonium produced at power plants contains close to 30% of it, and since the trick of separating isotopes doesn’t work with Plutonium (it’s literally too hot to handle) you are stuck with whatever isotope fractions come out of the reactor at the end of the fuel cycle. The total quantity of plutonium recycled each year throughout the world is around 70 tonnes.
The ability to produce useful Pu-239 from (almost) useless U-238 in nuclear reactors stretches out the uranium reserves. The conversion ratio is typically between 0.5 and 0.8, meaning that more U-235 is used up than Pu-239 is created to replace it. This is a problem, since uranium reserves are finite and increasingly difficult and expensive to produce. But if this problem were to be solved and the conversion ratio raised above 1, then the amount of U-238 already produced would be sufficient to power industrial economies for thousands (yes, literally, thousands) of years.
And what if I told you that this problem is well on the way to being solved? Furthermore, what if the other really huge problem—of what to do with high-level nuclear waste (of which there are 250000 tonnes in the world) is also well on the way to being solved? (A way has been found to burn up almost all of it in nuclear reactors.) Lastly, what if I told you that solutions have also been found to the problem of nuclear reactors blowing up and melting down once in a while? (This last one is also a very serious issue. The Fukushima Daichi disaster has been estimated to cost at least $500 billion and has pretty much nuked the Japanese nuclear industry).
I will eventually get around to explaining what these solutions look like. Again, I don’t wish to try to change anyone’s attitude toward nuclear power, mostly because it doesn’t matter. You are no more likely to be able to put a stop to it if you tried than you are to be able to run out and buy yourself a nuclear reactor. Rest assured, the issue is safely out of your hands. But it may help you to be informed about it. As with most kinds of technology, once it is created and proved to be useful and effective, it is going to be used. Those who use it will win and get to play again, those who don’t will lose and drop out of the game, and the world will move on.
Before I expound on these solutions, I would like to address a few other, related issues. One is the environmental impact of the nuclear industry compared to that of the fossil fuel industry and renewables. Another is the state of nuclear industry around the world and its general viability, which is in many places questionable regardless of what solutions may exist. And a final, very major issue is the problem of radiophobia: it seems that radiation scares people much more than it ought to. Yes, radiation can be dangerous, but so can a baseball bat to the head. The only difference is that baseball bats are visible and radiation often isn’t, and people tend to be much more scared of invisible dangers than of visible ones. I will take up these issues next.