Unfortunately, atompunk hasn't enjoyed as much success (yet) as its steam-powered cousin. The quintessential modern exemplar is the Fallout series, and the Venture Brothers cartoons sometimes venture into atompunk territory, but for other examples we mostly have to go back to the '50s and '60s: the novels of Asimov and Heinlein, the Tom Swift Jr. young adult books, and the original Star Trek series.
The common belief is that atompunk is, in retrospect, implausible. Space travel and atomic energy are a lot harder, and a lot more expensive, then they seemed in 1950s pulp science fiction, and by this point it's pretty clear that Mars is not home to green-skinned space babes eager to meet some Intrepid Explorers. Technology gave us iPods and the internet instead of moon colonies and atomic cars.
That perception is not totally wrong – radiation causes cancer, not gigantism – but it's not totally right, either. Something close to the classical atompunk world is not impossible – it's not a likely outcome of the last seventy years of history, but it's not impossible. And I'm here to tell you how it could have happened, at least in fiction: how to write a technically realistic atompunk timeline. I'm going to tell you about atomic-powered airplanes, atomic excavation, cheap atomic power, and more about radiation then you ever wanted to know.
Buckle in, folks.
Also, consider language. You can capture a lot of style by using deliberately archaic word choices from the 1950s. A computer is a “logic”. A satellite is a “sputnik”. A nuclear-powered submarine or ship is an “A-sub” or “A-ship.” And don't ever say nuclear: always say “atomic.” Proper attention to language – making your story sound like it comes from the 1950s – will help a lot to make your reader feel like it's from the 1950s, or at least the future as the 1950s imagined it.
But like I said, that's the easy stuff. Now let's talk about the hard stuff, and let's begin in the obvious place: radiation. The conventional wisdom is that the discovery of radiation, and the fact that it's bad for you, is why the 747 isn't powered by an atomic engine. This conventional wisdom is not exactly wrong, but the full truth is a lot more complicated then most people think.
Most of what we know about how radiation effects human health comes from studying the victims of the Hiroshima and Nagasaki bombings. Because the vast majority of radiation produced by the bombs was produced all at once at a single point, we can calculate how much radiation each victim was exposed to, based on where they were when the bombs went off. By comparing the radiation exposure to the victims' medical histories, we get a pretty good idea of what happens to someone when they are exposed to a lot of radiation all at once.
For this article, I'm going to use millisieverts (mSv) as the measure of radiation. In the data from the bombing victims, we begin to see people suffering radiation sickness above 1,000 milliSieverts (mSv) exposure, and we see an increase in cancer risk above 100 mSv exposure, at a rate of about 1% per 100 mSv. So someone exposed to 300 mSv has a 3% increase in cancer risk, 600 mSv means 6%, etc. Since roughly the mid-70s, we have assumed that we can extrapolate the risk downwards: so 10 mSv exposure means a 0.1% increase in cancer risk, etcetera. We have also assumed that the rate of exposure doesn't make a difference to cancer risk: absorbing 100 mSv in a second is the same as absorbing it over a year. This is based on the simple assumption that cancer risk is caused by DNA damage, and the amount of damage is directly proportional to the amount of ionizing radiation you absorb. This is called the Linear No-Threshold hypothesis, or LNT.
The reason this matters is that, in a radiation accident like Chernobyl or Fukushima, the vast majority of victims will be exposed to very small doses of radiation spread out over a very long period of time. In a reactor accident, very few people will be exposed to a radiation dose of more than 50 mSv, and it will be delivered over weeks or months. Even under the LNT hypothesis, the individual risk is very low – but many thousands or millions of people will be exposed to that risk. If you expose a million people to a 10 mSv dose, and the LNT hypothesis is correct, then 1,000,000 times 0.1% equals 1,000 people will get cancer, and about half will die of it. That's why atomic technology is regulated so tightly – the individual risks are very small, but the collective risks can be very large.
In the meantime, Western regulatory agencies are sticking with the LNT hypothesis out of an abundance of caution. And, in the real world, I think that is the right decision. If we regulate based on LNT, and we're wrong, then we've wasted a lot of money. If we regulate based on LT, and we're wrong, then people die.
But we're not talking about the real world. We're talking about fiction. In fiction, we can make whatever assumptions we want. And if we assume the LT hypothesis is true, then a reactor meltdown is just an industrial accident – it's not a good thing, but it's no worse then any other accident involving toxic chemicals. And this is the key to making an atompunk world possible.
And a lot of the wild atomic technology imagined in the '50s really is viable if we make that assumption. Electricity from fission really can be cheap. Atomic-powered airplanes and spaceships really can be safe and practical. We really can dig canals with hydrogen bombs. Some things still aren't feasible, and there are still question marks attached to some of these ideas that have nothing to do with safety or economics. But a lot of seemingly crazy things suddenly become good ideas.
The first of these technologies I'd like to talk about is the atomic-powered airplane, which is even cooler then it sounds. I'm going to call it the A-plane, by analogy to the A-bomb, because I think it sounds cooler that way. Even in our own world, the Aircraft Nuclear Propulsion (ANP) program was an enormous undertaking. It lasted fifteen years, from 1946 to 1961, and cost the equivalent of about $20 billion in today's money. The goal was to build an atomic-powered bomber, able to remain aloft for weeks.
Today, at first glance, the idea seems insane. What if the thing crashes? But this is where the distinction between LNT and LT comes in. Under the LT hypothesis, if an A-plane crashes, only the immediate area around the crash site is going to have to worry about radioactive contamination. Again, under the LT hypothesis, a radiation accident is just an industrial accident like any other: not good, but not a major catastrophe. And since, in the '50s, the atomic energy community was tacitly or explicitly operating under the LT hypothesis, that's why they were willing to pursue this concept.
And the thrust/weight ratio was very important. One of the big problems with the ANP program was that, even if you count the fuel in a conventional turbojet as part of the “engine”, an atomic engine is usually going to weigh more then a conventional engine and produce less thrust. By the end of the program, ANP knew how to build an atomic-powered airplane, but that airplane would have been big, expensive, and slow – not what you'd want penetrating Soviet airspace. A big part of the problem was that the Air Force could never make up its mind whether or not they really wanted the plane – they were perpetually ramping up and cutting back funding, shifting into crash priority mode and then downscaling to feasibility studies.
Let's suppose that the Pentagon provides reliable support for the A-plane instead of our own timeline's oscillation. This could be accomplished by just changing Eisenhower's Secretary of Defense – part of the problem for the program historically was that Secretary Quarles thought the whole idea was absurd. The really interesting part is not what could be built in the 1950s, but where this would push airplane technology in the '60s and '70s.
The thrust/weight ratio of an atomic engine improves – a lot – as the weight of the airplane increases. A heavier airplane needs a more powerful engine. The power of an atomic engine is proportional to its volume. But the weight of that engine is dominated by the weight of its radiation shielding, which is proportional to its surface area. And the ratio of surface area to volume decreases as the volume increases – so the thrust/weight ratio improves as the engine gets bigger. For a big enough plane, the thrust/weight ratio of an atomic engine is better then a conventional engine.
How big? That depends a lot on the specifics of your reactor. But we're typically talking about a plane north of a million pounds takeoff weight, and the bigger the better. NASA studies in the '60s and '70s envisioned civilian A-planes of ten to twenty million pounds takeoff weight. The heaviest plane that has ever flown in our world, the Antonov An-225 Mriya, has a maximum takeoff weight of about 1.4 million pounds. So these are enormous aircraft – but for us, that's an asset, not a liability. Imagine a monster flying wing, thirty times the size of the 747 – big enough to carry a Saturn-V rocket – slowly cruising past the sunset. Lockheed, at one point, floated the idea of an atomic-powered flying aircraft carrier based on this concept. How much cooler can you get?
But where things get really interesting is when we start looking at what we could do with an atomic turbojet on the ground.
Too Cheap to Meter
The original “too cheap to meter” comment was actually talking about fusion, not fission, but it's too iconic a comment to pass up.
Historically, the cost of atomic energy has been, at best, disappointing. Even in places where atomic energy is competitive with coal and gas, it's only competitive. It was supposed to mark a new industrial revolution, where cheap energy would make all manner of new goods and services possible. Maybe we can't get quite that far, but we can get a lot closer then we did.
To begin with, let's talk a little bit about the history of atomic energy. The vast majority of the atomic reactors in the West evolved from reactors developed to power submarines, called Light Water Reactors, or LWRs. These reactors use solid fuel elements made of enriched uranium oxide ceramic, cooled and moderated by pressurized water, with the heat turned into electricity in a steam turbine. These designs were chosen for for two reasons: first, because they're (relatively) simple, and second, because they could piggy-back off of the enormous amount of research that had already been done on these designs for submarines.
But, in retrospect, these weren't necessarily the best kind of reactor we could have chosen to use to make electricity. There are a lot of ways to split an atom; I once tried to make a list of all of the seriously proposed types, and stopped after I hit forty. To illustrate, let's break our reactors down on fuel type, coolant, and moderator – a vast over-simplification if ever there was one:
Uranium Oxide Ceramic
Solid Metal Alloy
Carbide or Nitride Ceramic
Molten Metal Alloys
Molten Fluoride Salts
Molten Chloride Salts
Uranium Hexafluoride Gas
Sulfate Salts Dissolved in Water
A lot of these proposals can be discarded because, in retrospect, they were clearly bad ideas. But many of them might have been good ideas, possibly better ideas then the LWRs we ended up building. But it takes a lot of money to turn a reactor concept into a working prototype, and then even more money to turn a prototype into a design that can be rolled out commercially. And that money just wasn't there for most of these proposals – as I mentioned, a big part of why the LWR became the dominant reactor type was because a huge amount of money had already been spent by the Navy. For the followup to the LWR, the US Atomic Energy Commission chose the liquid-metal-cooled fast breeder reactor (LMFBR), and the cost of trying to build a commercial LMFBR prototype led to the cancellation of their other reactor research programs. But the LMFBR was a massive flop – far too expensive to compete, and with questionable safety characteristics (the coolant is flammable). When congress finally killed the LMFBR in the '80s, research into other alternatives was already long dead in the United States, it has only recently begun to tentatively revive.
But we were just talking about the A-plane. If A-planes fly, then a second class of reactors is going to get that same kind of development subsidy, this time from the Air Force. A direct-cycle atomic engine could be used as the basis for a gas-cooled power reactor, and in the long run, such a machine could have significant advantages over a light water reactor. Power from these reactors probably wouldn't be “too cheap to meter”, but, between lighter radiation regulations and a better base reactor technology, they could be much cheaper then the LWRs we have today – cheap enough to out-compete coal and gas.
And that has its own implications, most of which are beyond the scope of this essay. To mention a few, though: cheap electricity means cheap plastic trinkets are replaced with cheap aluminum trinkets. Large-scale desalination is feasible as a solution to water shortages. Carbon emissions are radically lower – we'd still burn gasoline in our cars, but we would see natural gas drastically decline, and coal perhaps eliminated altogether. Cheap, clean energy would have enormous, and to some extent unforeseeable, implications.
The Atomic Shovel
Frankly, even in a world where radiation isn't a big deal, it's not at all clear that atomic geographical engineering is practical. There are two main issues. The first is economic: even in a world using the Linear Threshold hypothesis, an area where atomic excavation is being used is going to have to be evacuated for about two years until the initial radiation dies down. Plus, ground shock means that any buildings in the area will suffer serious structural damage. These two facts mean that you can't use atomic excavation anywhere near where lots of people live – but if not many people live there, what's your new canal for? There are a few places where it might make sense – such as excavating harbors for mines in remote locations – but it's unclear if there are enough such places to justify the cost of developing the technology in the first place.
A more subtle problem, but in the long run more dangerous, is proliferation. If the United States is using atomic devices for excavation, it becomes much more difficult to tell other countries that they can't have them. Even in our own timeline, this was a serious problem – India, for example, initially insisted that its first atomic test was for peaceful purposes, and the Nuclear Non-Proliferation Treaty includes a clause guaranteeing that the weapons states will provide “peaceful nuclear explosives” to non-nuclear states on request.
But states aren't the only problem. We're talking about building and detonating dozens – perhaps hundreds – of atomic explosives per year, and shipping them all over the world for industrial use. I would be concerned about one of them disappearing, and then reappearing inside a crowded city. Now, the NATO militaries – and probably the Russians – did keep large numbers of tactical nuclear weapons in relatively insecure facilities for decades without losing any (that we know of), but it seems like pushing one's luck.
I'm going to keep this section brief, because Project Orion is one of the few historical atompunk concepts that is fairly well-known. For those who haven't heard of it, Orion would have used atomic bombs to launch spacecraft.
An Orion spaceship would consist of a gigantic metal plate. Atomic bombs would be dropped through a hole in the plate and detonate underneath, and the shockwave would push the ship forward.
On paper, such a ship is an extremely efficient way both to launch material from Earth into space, and to move it around in space once it gets there. In fact, in a purely technical sense, it is by far the best space drive by almost any measure that could be built with present technology. A single Orion launch could lift thousands of tons of cargo into orbit at a low cost per kilogram, and, once in orbit, could carry it to anywhere in the solar system. A world using Orion drives would have had a manned expedition to Mars by now at the very least.
In our world, Orion was killed by the Partial Test-Ban Treaty of 1963, which effectively prohibits atomic detonations in the air or in space. The PTBT was primarily driven by concerns over the health effects of atomic testing, so in a world using the LT hypothesis, it will not be signed – and it is quite possible that Orion will fly.
That said, I would like to point out that there are still a number of unanswered questions about Orion's technical feasibility, particularly regarding whether the energy from the explosions can be properly directed, whether the pusher-plate will hold up to repeated detonations, and just how much all this will cost. Still, compared to the other assumptions we've made, these are relatively small, and the technical hurdles for Orion are no worse than for any other proposed way to get into space for dollars per kilogram.
What We Can't Do
So what parts of the atompunk dream aren't possible, at least not in the 20th century?
Well, atomic-powered cars are definitely Not Happening. It might just be barely theoretically possible to build a reactor small enough to power a car – maybe – but it definitely couldn't be built at a price anyone could afford, even a billionaire. And you'd have to fuel it with weapons-grade fuel, which the government would presumably frown on. So that's not going to happen.
The traditional nuclear thermal rocket probably isn't practical either. A nuclear thermal rocket (NTR) uses a nuclear reactor to heat a fluid – usually hydrogen – which is then used as exhaust. Unlike an Orion, which looks like a gigantic plate on top of an explosion, an NTR would look like a “classical” rocket like the Saturn-V. Like the A-plane, NTRs were the focus of a major AEC/NASA research effort in the '60s that is now largely forgotten. However, Orion drives outperform nuclear thermal rockets on every metric. If you take Orion off the table, it is theoretically possible to build a nuclear thermal rocket with a thrust/weight ratio high enough for Earth launch, but it requires either liquid oxygen augmentation – which eliminates almost all of the efficiency advantage – or materials that don't exist today, and probably won't exist in this half of the 21st century. The most we might see would be a nuclear-powered upper stage with a conventional lower stage, like the TIMBERWIND proposal in the 1980s, but it's tough to make that make sense economically. Even once you reach orbit, nuclear thermal rockets might have a niche, but it won't be a big one – nuclear- or solar-powered ion drives can do most of the same things, but better. So, all in all, it's tough to see them finding a role to play. Which is a shame, because I really prefer the aesthetics of the nuclear rocket to the Orion – a gleaming, needle-nosed rocket is such a classic atompunk motif.
I hope that this essay has sparked some ideas. Before I leave you, though, I'd like to call back to something I mentioned at the start.
The Linear Threshold hypothesis really might be true. We don't know and we can't know right now, but scientists continue to work on understanding how ionizing radiation effects human cells. And someday, we may finally figure it out, we may prove one of these dueling hypotheses. And the right answer might turn out to be the Linear Threshold hypothesis.
We may wake up one morning, turn on the internet, skim through the science news – and discover that quietly, subtly, the world has changed. That a lot of regulations we thought were necessary really weren't. That atomic energy really can be cheap, and that Orion ships really can be built without killing people. That we really can have the world our parents dreamed of.
This isn't just alternate history. It's a possible future.
So keep an eye on the science news. Because you never know.
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Mark J. Appleton blogs on atompunk history at Atomic Skies.