As the topic says, was it (or is it) ever possible for nuclear vehicles (not counting aircraft or ships) to be a common sight on roadways or railroads? Assuming that we truly had an "atomic era" where nuclear power was able to become the dominant power source for society.
I'll get this out of the way too, I don't mean anything like the Ford Nucleon. It is physically impossible to make a reactor that small, and even the smallest reactors would be utterly wasted in a passenger vehicle. The only possibility I've heard is that an isotope of americium can in theory produce an incredibly small (about basketball-sized IIRC) reactor. But even that I doubt would be feasible for powering a passenger vehicle, although it would be good for powering a large truck or a train.
The solution to nuclear vehicles is a radioisotope thermal generator (RTG), which is powered by the decay heat from radioisotopes. IOTL, these are used mainly on space probes and remote installations in the Arctic (lighthouses, monitering posts, etc.). These can be miniaturised and potentially used as fuel for vehicles. The advantage is that if you use the right isotope, your vehicle can go for years without refueling. And in theory, potentially you could plug your car in when it was parked to feed energy back into the grid. IIRC, there's similar concepts like a betavoltaic battery, which is powered by beta radiation. Either would work, and it's still a nuclear car.
Presumably, this would eliminate gas stations, since the car would almost never need fuel. Depending on the isotope used, an RTG could go without fueling the entire lifespan of the vehicle, although you might need to refuel it every few years. This would be done at specific facilities with trained technicians.
The best sources would appear to be plutonium-238, strontium-90, and curium-244. Pu-238 might be the best since it's half-life of 87 years means the vehicle would likely never need refueling, since noticeable power loss would not occur for decades--it also needs minimal shielding, reducing the weight of the vehicle. Sr-90 is more power dense than Pu-238, but needs more shielding and only has a half-life of 28 years--however, Sr-90 is by far the cheapest of these isotopes to produce. Cm-244 only has a half-life of 18 years and is expensive, but is more power dense (although makes up for it by needing more shielding). Spent fuel sources would be recycled in some form, probably by conversion back into nuclear fuels although Sr-90 is rather less useful.
The biggest problem is of course car accidents. Millions of car accidents occur in developed nations, and developing nations are even worse in terms of vehicle accidents per capita. A serious car accident has a high chance of spewing radioactive materials all over the roadway. This would be a Level 2 incident (IIRC) on the International Nuclear Event Scale. Disposal of old cars would become a major concern, and security could be breached. In Russia, for instance, some of their RTGs have been broken into and stolen by thieves. Events like the Goiânia accident could be common in such a society. The material in an RTG is useful for building dirty bombs, so if RTGs are everywhere, acquiring nuclear materials is thus pretty easy and dirty bombs are far easier to construct.
Cancer might be a concern, but the number of nuclear power plants needed to produce the required material would be far worse for public health. However, the common availability of radioisotopes would probably mean better (and cheaper) treatments for many forms of cancer so I'd expect the number of deaths from cancer to be lower than OTL.
This is why passenger vehicles powered on nuclear fuel would never become common before self-driving cars are universal. Only large commercial vehicles might be powered by nuclear fuel, and probably only some companies would use them. These vehicles would have better shielding and their size makes them less vulnerable to catastrophic accidents which would cause their radioactive fuel to be released. Nuclear trains would be a potential as well under current technology.
When self-driving cars are universal on the roadway (the era when driving manually on a public roadway will be just as illegal as drunk driving), I could see most cars being powered by RTG engines. The rate of car accidents will be way down, and many vehicles will likely be taken off the roadway in general as personal vehicle ownership becomes less common, further reducing the risk of accidents.
The fuel savings are pretty incredible, given that billions of gallons of fuel is no longer needed. This would have huge economic benefits at many levels, from reduced transportation costs to additional household income.
Is any of this a plausible or realistic development of 20th century technology, or perhaps more something we might see in the future? Was it ever plausible for nuclear trains or semi-trucks to be common?
I'll get this out of the way too, I don't mean anything like the Ford Nucleon. It is physically impossible to make a reactor that small, and even the smallest reactors would be utterly wasted in a passenger vehicle. The only possibility I've heard is that an isotope of americium can in theory produce an incredibly small (about basketball-sized IIRC) reactor. But even that I doubt would be feasible for powering a passenger vehicle, although it would be good for powering a large truck or a train.
The solution to nuclear vehicles is a radioisotope thermal generator (RTG), which is powered by the decay heat from radioisotopes. IOTL, these are used mainly on space probes and remote installations in the Arctic (lighthouses, monitering posts, etc.). These can be miniaturised and potentially used as fuel for vehicles. The advantage is that if you use the right isotope, your vehicle can go for years without refueling. And in theory, potentially you could plug your car in when it was parked to feed energy back into the grid. IIRC, there's similar concepts like a betavoltaic battery, which is powered by beta radiation. Either would work, and it's still a nuclear car.
Presumably, this would eliminate gas stations, since the car would almost never need fuel. Depending on the isotope used, an RTG could go without fueling the entire lifespan of the vehicle, although you might need to refuel it every few years. This would be done at specific facilities with trained technicians.
The best sources would appear to be plutonium-238, strontium-90, and curium-244. Pu-238 might be the best since it's half-life of 87 years means the vehicle would likely never need refueling, since noticeable power loss would not occur for decades--it also needs minimal shielding, reducing the weight of the vehicle. Sr-90 is more power dense than Pu-238, but needs more shielding and only has a half-life of 28 years--however, Sr-90 is by far the cheapest of these isotopes to produce. Cm-244 only has a half-life of 18 years and is expensive, but is more power dense (although makes up for it by needing more shielding). Spent fuel sources would be recycled in some form, probably by conversion back into nuclear fuels although Sr-90 is rather less useful.
The biggest problem is of course car accidents. Millions of car accidents occur in developed nations, and developing nations are even worse in terms of vehicle accidents per capita. A serious car accident has a high chance of spewing radioactive materials all over the roadway. This would be a Level 2 incident (IIRC) on the International Nuclear Event Scale. Disposal of old cars would become a major concern, and security could be breached. In Russia, for instance, some of their RTGs have been broken into and stolen by thieves. Events like the Goiânia accident could be common in such a society. The material in an RTG is useful for building dirty bombs, so if RTGs are everywhere, acquiring nuclear materials is thus pretty easy and dirty bombs are far easier to construct.
Cancer might be a concern, but the number of nuclear power plants needed to produce the required material would be far worse for public health. However, the common availability of radioisotopes would probably mean better (and cheaper) treatments for many forms of cancer so I'd expect the number of deaths from cancer to be lower than OTL.
This is why passenger vehicles powered on nuclear fuel would never become common before self-driving cars are universal. Only large commercial vehicles might be powered by nuclear fuel, and probably only some companies would use them. These vehicles would have better shielding and their size makes them less vulnerable to catastrophic accidents which would cause their radioactive fuel to be released. Nuclear trains would be a potential as well under current technology.
When self-driving cars are universal on the roadway (the era when driving manually on a public roadway will be just as illegal as drunk driving), I could see most cars being powered by RTG engines. The rate of car accidents will be way down, and many vehicles will likely be taken off the roadway in general as personal vehicle ownership becomes less common, further reducing the risk of accidents.
The fuel savings are pretty incredible, given that billions of gallons of fuel is no longer needed. This would have huge economic benefits at many levels, from reduced transportation costs to additional household income.
Is any of this a plausible or realistic development of 20th century technology, or perhaps more something we might see in the future? Was it ever plausible for nuclear trains or semi-trucks to be common?