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Nuclear technology scales horribly downwards so even in a world that fully-embraced the technology you won't have pocket reactors that do anything more than may

Nuclear technology scales horribly downwards so even in a world that fully-embraced the technology you won't have pocket reactors that do anything more than maybe a power some gimmick accessory. The true power potential of nuclear only comes into affect with full steam boiler-turbine infrastructure, which are large, heavy, and maintenance-intensive beasts; a good comparison would be an early-industrial coal steam boiler from the time before we really understood metallurgy. You'd have those boilers in factories, ships, and trains, and maybe even a small crappy one if you were rich for the home workshop, but nothing you'd carry around. RTGs can be made small, but they also completely sacrifice the power density of nuclear due to their abysmal efficiency. Their main advantage is maintenance-free longevity more so than compactness or anything.

londons_explore 7y ago
I think with investment nuclear technology could scale down - the full steam boiler design could maybe even be miniaturized via silicon micro machines type technology, but there might also be avenues for using the photoelectric effect for a more direct nuclear to electricity conversion. Either way, I can totally imagine someone saying "punch cards and relays scale down horribly - you could never make a small computer".
AnthonyMouse 7y ago
> Nuclear technology scales horribly downwards A small steam turbine is an apparatus with about the size and complexity of a car engine. But if it has to be licensed and inspected by the NRC then you can forget about it. And you could make a little RTG that could power a phone for a decade. Even with the terrible efficiency of thermoelectric generators it would still be much smaller than a lithium battery that could store the same number of kWh, because it's ~10% of the efficiency multiplied by much more than 10 times the power density. The main limit you hit on size is practicality -- why make a tiny, tiny, tiny one that lasts for a month when you can make an only marginally larger one that lasts for ten years?
- waste_monk 7y ago
  I'd accept a thick phone if it had a huge battery life. But then how do you perform waste disposal? People are, largely, irresponsible jackasses who would think nothing of throwing old RTGs into the ocean / landfill / other improper decomissioning methods. Also the potential damage is a lot higher e.g. if you're in a car accident and the RTG gets punctured vs. just a Li-ion battery catching fire. In terms of cleanup and containment.
  - AnthonyMouse 7y ago
    Using an RTG to power your phone isn't a real suggestion. Lithium batteries can last for a day (especially if you're willing to accept a thicker phone) and the inconvenience of having to charge it while you're asleep is minimal. A more realistic application might be something like military radios where you may want them to keep working for extended periods of time in areas where electricity is not available, and then you have an organizational structure that can take care of proper disposal. The point is that it's not a scaling problem. It's practical to make an RTG that small as a technical matter.

londons_explore 7y ago

I think with investment nuclear technology could scale down - the full steam boiler design could maybe even be miniaturized via silicon micro machines type technology, but there might also be avenues for using the photoelectric effect for a more direct nuclear to electricity conversion. Either way, I can totally imagine someone saying "punch cards and relays scale down horribly - you could never make a small computer".

AnthonyMouse 7y ago

> Nuclear technology scales horribly downwards A small steam turbine is an apparatus with about the size and complexity of a car engine. But if it has to be licensed and inspected by the NRC then you can forget about it. And you could make a little RTG that could power a phone for a decade. Even with the terrible efficiency of thermoelectric generators it would still be much smaller than a lithium battery that could store the same number of kWh, because it's ~10% of the efficiency multiplied by much more than 10 times the power density. The main limit you hit on size is practicality -- why make a tiny, tiny, tiny one that lasts for a month when you can make an only marginally larger one that lasts for ten years?

waste_monk 7y ago
I'd accept a thick phone if it had a huge battery life. But then how do you perform waste disposal? People are, largely, irresponsible jackasses who would think nothing of throwing old RTGs into the ocean / landfill / other improper decomissioning methods. Also the potential damage is a lot higher e.g. if you're in a car accident and the RTG gets punctured vs. just a Li-ion battery catching fire. In terms of cleanup and containment.
- AnthonyMouse 7y ago
  Using an RTG to power your phone isn't a real suggestion. Lithium batteries can last for a day (especially if you're willing to accept a thicker phone) and the inconvenience of having to charge it while you're asleep is minimal. A more realistic application might be something like military radios where you may want them to keep working for extended periods of time in areas where electricity is not available, and then you have an organizational structure that can take care of proper disposal. The point is that it's not a scaling problem. It's practical to make an RTG that small as a technical matter.