13 ms·

> Long-distance oceanic shipping is another area where hydrocarbon fuels might be necessary, although there are some other options (wind/solar/iron redox). Yea

> Long-distance oceanic shipping is another area where hydrocarbon fuels might be necessary, although there are some other options (wind/solar/iron redox). Yeah, and nuclear, which is deployed at huge scale in seafaring vessels in the Navy. Merchant nuclear propulsion had an early start and is likely to see a revival imho. https://en.wikipedia.org/wiki/NS_Savannah https://en.wikipedia.org/wiki/NS_Savannah https://corepower.energy/ https://corepower.energy/ https://en.wikipedia.org/wiki/Nuclear_marine_propulsion https://en.wikipedia.org/wiki/Nuclear_marine_propulsion

eloff 4y ago
Only if they can do it cheaper than the Navy. Nuclear isn't used because it saves on fuel. It's used because the operational advantages it bestows are worth more for the largest carriers and submarines than the extra cost it adds.
- acidburnNSA 4y ago
  I agree that merchant nuclear-powered vessels will need to be cheaper than Naval nuclear-powered vessels. That is the goal. An international carbon tax or other credits for low-carbon/low-emission shipping would help.
celtain 4y ago
Wow, I had no idea that there's currently a nuclear powered cargo ship in service: https://en.m.wikipedia.org/wiki/Sevmorput https://en.m.wikipedia.org/wiki/Sevmorput I'd love to see it, but I'm a bit pessimistic about the political viability of a significant revival of civilian nuclear ships.
- acidburnNSA 4y ago
  I was excitedly watching its journey down to Antarctica a few years ago. Sadly it had a propeller maintenance issue and had to turn around. :'(
photochemsyn 4y ago
A major reason military naval systems are efficient is that they don't need to be refueled very often - but that's because their fuel is highly-enriched uranium, bomb-grade HEU which 'burns' much cleaner (and can be diverted to an actual gun-type nuclear weapon, Hiroshima-type). That's just not going to happen with commercial shipping. A commercial nuclear-powered cargo ship would have to be refueled on the same time scale as a commercial MOX or LEU reactor, likely raising costs quite a bit over any other fuel. Plus, what harbor would allow commercial nuclear reactors, given the costs of catastrophic failure, without ridiculously expensive levels of security and safeguards?
- ClumsyPilot 4y ago
  > Plus, what harbor would allow commercial nuclear reactors, given the costs of catastrophic failure These ports already handle tens of thousands of tons of explosives - the blast in Beirut wa over 1 Kt of TNR equivalent, and all that ammonium nitrate arrived on a single ship. It was basically a small nuclear detonation.
  - Schroedingersat 4y ago
    How many billions did dredging all the Caesium out of the harbour and evacuating the entire area for a few months to avoid the Iodine plume from the nitrate explosion cost?
- acidburnNSA 4y ago
  The major threat to a nuclear reactor is loss of afterglow heat cooling, which is extra unlikely when you're surrounded by water. That said, one interesting approach is to use ocean-faring nuclear-powered tugs that basically stay out in international water and hand off massive container barges to little fossil fueled short-haul ones that can take it in to port where people are afraid of nuclear fission but don't care about air pollution or climate change. As for refueling, it's true that submarines don't need to refuel for 30 years. But there's a lot more room on a container ship, so you can make a big core and run it at less than full power. This way you can get it to only need refueling every 5 years or so with low-enriched uranium. Not bad. Nuclear tugs: https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1559-3584.1963.tb04392.x https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1559-3584....

eloff 4y ago

Only if they can do it cheaper than the Navy. Nuclear isn't used because it saves on fuel. It's used because the operational advantages it bestows are worth more for the largest carriers and submarines than the extra cost it adds.

acidburnNSA 4y ago
I agree that merchant nuclear-powered vessels will need to be cheaper than Naval nuclear-powered vessels. That is the goal. An international carbon tax or other credits for low-carbon/low-emission shipping would help.

celtain 4y ago

Wow, I had no idea that there's currently a nuclear powered cargo ship in service: https://en.m.wikipedia.org/wiki/Sevmorput https://en.m.wikipedia.org/wiki/Sevmorput I'd love to see it, but I'm a bit pessimistic about the political viability of a significant revival of civilian nuclear ships.

acidburnNSA 4y ago
I was excitedly watching its journey down to Antarctica a few years ago. Sadly it had a propeller maintenance issue and had to turn around. :'(

photochemsyn 4y ago

A major reason military naval systems are efficient is that they don't need to be refueled very often - but that's because their fuel is highly-enriched uranium, bomb-grade HEU which 'burns' much cleaner (and can be diverted to an actual gun-type nuclear weapon, Hiroshima-type). That's just not going to happen with commercial shipping. A commercial nuclear-powered cargo ship would have to be refueled on the same time scale as a commercial MOX or LEU reactor, likely raising costs quite a bit over any other fuel. Plus, what harbor would allow commercial nuclear reactors, given the costs of catastrophic failure, without ridiculously expensive levels of security and safeguards?

ClumsyPilot 4y ago
> Plus, what harbor would allow commercial nuclear reactors, given the costs of catastrophic failure These ports already handle tens of thousands of tons of explosives - the blast in Beirut wa over 1 Kt of TNR equivalent, and all that ammonium nitrate arrived on a single ship. It was basically a small nuclear detonation.
- Schroedingersat 4y ago
  How many billions did dredging all the Caesium out of the harbour and evacuating the entire area for a few months to avoid the Iodine plume from the nitrate explosion cost?
acidburnNSA 4y ago
The major threat to a nuclear reactor is loss of afterglow heat cooling, which is extra unlikely when you're surrounded by water. That said, one interesting approach is to use ocean-faring nuclear-powered tugs that basically stay out in international water and hand off massive container barges to little fossil fueled short-haul ones that can take it in to port where people are afraid of nuclear fission but don't care about air pollution or climate change. As for refueling, it's true that submarines don't need to refuel for 30 years. But there's a lot more room on a container ship, so you can make a big core and run it at less than full power. This way you can get it to only need refueling every 5 years or so with low-enriched uranium. Not bad. Nuclear tugs: https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1559-3584.1963.tb04392.x https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1559-3584....