5 ms·

Or fission...

snerbles 7y ago
See also the NS Savannah, the first nuclear-powered merchant ship. https://en.wikipedia.org/wiki/NS_Savannah https://en.wikipedia.org/wiki/NS_Savannah
nradov 7y ago
Fission isn't practical for merchant vessels. Several large ships sink every year due to severe weather, structural failure, cargo shifting, etc. And there's no way to protect those ships against terrorist attacks. Use fission plants ashore to create synthetic liquid hydrocarbon fuel for ships. Fusion (if it ever works) will be too large and complex to use in merchant vessels.
- Accujack 7y ago
  Fission hasn't been practical in the past using old reactor technology. Climate change makes a big difference in the equation, though. Marine nuclear power is one of the best understood, safest areas of nuclear use that exists, even using the old technologies. The idea of using "modern sailing vessels" for shipping in the amounts that are presently moved from continent to continent is just plain nuts. Unless most of the world is willing to go back a hundred years in technology, we're going to need to use motor vessels going forward. About the only way to eliminate all carbon emissions from large ships is to make them reactor powered. Batteries will work for short trips, but if you combine the need for long range and high power in shipping of large cargoes, the only way to power ocean going vessels in any practical sense are internal combustion engines running on fossil fuels or steam generating reactors powering turbines. That's why the navies of the world run on one or the other.
  - nradov 7y ago
    New fission reactor technology won't change anything. Only the US Navy has a good safety record with nuclear vessels; the Soviet / Russian Navy has had multiple serious accidents with sinkings and radiation releases. And the only way the US Navy succeeded was by using a huge amount of resources under tight top-down control. None of that is possible in the merchant fleet. Plus the Navy has built in armed security forces. Any modern nuclear merchant vessel would need armed, trusted security guards to protect against terrorist attacks (just like nuclear plants ashore). In short, nuclear powered merchant ships are never going to happen regardless of the potential advantages.
    - Accujack 7y ago
      Both navies have had incidents where nuclear powered submarines sank. That's the nature of the military, they tend to go places other ships don't. > the only way the US Navy succeeded was by using a huge amount of resources under tight top-down control. Everything in the military is done with tight top down control for the most part. That's not why it succeeded, though. The military is the only organization that did it since it's the only organization for which nuclear wasn't constrained by the need for profit. There was a demonstration nuclear cargo vessel built that operated for four years, but they weren't mass produced and so weren't economically viable when oil was cheap. However, if you combine the need for lowered emissions with the higher modern price of oil, larger scale production of nuclear civilian vessels begins to make some economic sense. This is aided also by the fact that modern reactors could be designed to be lower cost to operate. Security wise, nuclear powered vessels would be less vulnerable than oil powered vessels presently are because they'd be at least as fast and would need refueling less often. They would not be a more attractive target for terrorists than other ships despite nuclear propulsion, because the reactors can be designed to be tamper proof, meaning the only thing a terrorist in possession of a nuclear ship can do is sink it with little resulting fear or hardship for the country they are trying to affect. Water blocks radiation very effectively, and ships with sunken nuclear reactors don't spread radiation around, they contain it.
      - nradov 7y ago
        The security risks are primarily in port, plus insider threats. Do you really think that most nations would ever allow nuclear powered merchant vessels crewed by random foreigners to enter their ports? Regardless of the potential benefits it's just completely unrealistic in the post 9/11 world.
    - jandrese 7y ago
      Theoretically one of those hypothetical sealed thorium reactor designs might be suitable and safe enough for a merchant ship, but it's a hard thing to sell while oil is still cheap. Having one of these ships sink is not as terrible as you might think. Water is an excellent moderator and these very heavy elements will tend to stay on the ocean floor. There's a reason we store nuclear waste in big swimming pools.
- russdill 7y ago
  Cargo ships are currently using diesel engines that weight up to 2,300 tons and carry more than 15,000 tons of fuel. The ITER core currently weighs about 5100 tons. I'd expect refined fusion systems to be able to come down in weight. Even if all the supporting infrastructure weighed more than the combination of bunker oil and diesel engine, it'd have to be a lot more to negate the advantages. As far as too complex, that really depends on the commercialization potential of fusion and how complex final designs are.

Or fission...

See also the NS Savannah, the first nuclear-powered merchant ship. https://en.wikipedia.org/wiki/NS_Savannah https://en.wikipedia.org/wiki/NS_Savannah

nradov 7y ago

Fission isn't practical for merchant vessels. Several large ships sink every year due to severe weather, structural failure, cargo shifting, etc. And there's no way to protect those ships against terrorist attacks. Use fission plants ashore to create synthetic liquid hydrocarbon fuel for ships. Fusion (if it ever works) will be too large and complex to use in merchant vessels.

Accujack 7y ago
Fission hasn't been practical in the past using old reactor technology. Climate change makes a big difference in the equation, though. Marine nuclear power is one of the best understood, safest areas of nuclear use that exists, even using the old technologies. The idea of using "modern sailing vessels" for shipping in the amounts that are presently moved from continent to continent is just plain nuts. Unless most of the world is willing to go back a hundred years in technology, we're going to need to use motor vessels going forward. About the only way to eliminate all carbon emissions from large ships is to make them reactor powered. Batteries will work for short trips, but if you combine the need for long range and high power in shipping of large cargoes, the only way to power ocean going vessels in any practical sense are internal combustion engines running on fossil fuels or steam generating reactors powering turbines. That's why the navies of the world run on one or the other.
- nradov 7y ago
  New fission reactor technology won't change anything. Only the US Navy has a good safety record with nuclear vessels; the Soviet / Russian Navy has had multiple serious accidents with sinkings and radiation releases. And the only way the US Navy succeeded was by using a huge amount of resources under tight top-down control. None of that is possible in the merchant fleet. Plus the Navy has built in armed security forces. Any modern nuclear merchant vessel would need armed, trusted security guards to protect against terrorist attacks (just like nuclear plants ashore). In short, nuclear powered merchant ships are never going to happen regardless of the potential advantages.
  - Accujack 7y ago
    Both navies have had incidents where nuclear powered submarines sank. That's the nature of the military, they tend to go places other ships don't. > the only way the US Navy succeeded was by using a huge amount of resources under tight top-down control. Everything in the military is done with tight top down control for the most part. That's not why it succeeded, though. The military is the only organization that did it since it's the only organization for which nuclear wasn't constrained by the need for profit. There was a demonstration nuclear cargo vessel built that operated for four years, but they weren't mass produced and so weren't economically viable when oil was cheap. However, if you combine the need for lowered emissions with the higher modern price of oil, larger scale production of nuclear civilian vessels begins to make some economic sense. This is aided also by the fact that modern reactors could be designed to be lower cost to operate. Security wise, nuclear powered vessels would be less vulnerable than oil powered vessels presently are because they'd be at least as fast and would need refueling less often. They would not be a more attractive target for terrorists than other ships despite nuclear propulsion, because the reactors can be designed to be tamper proof, meaning the only thing a terrorist in possession of a nuclear ship can do is sink it with little resulting fear or hardship for the country they are trying to affect. Water blocks radiation very effectively, and ships with sunken nuclear reactors don't spread radiation around, they contain it.
    - nradov 7y ago
      The security risks are primarily in port, plus insider threats. Do you really think that most nations would ever allow nuclear powered merchant vessels crewed by random foreigners to enter their ports? Regardless of the potential benefits it's just completely unrealistic in the post 9/11 world.
  - jandrese 7y ago
    Theoretically one of those hypothetical sealed thorium reactor designs might be suitable and safe enough for a merchant ship, but it's a hard thing to sell while oil is still cheap. Having one of these ships sink is not as terrible as you might think. Water is an excellent moderator and these very heavy elements will tend to stay on the ocean floor. There's a reason we store nuclear waste in big swimming pools.
russdill 7y ago
Cargo ships are currently using diesel engines that weight up to 2,300 tons and carry more than 15,000 tons of fuel. The ITER core currently weighs about 5100 tons. I'd expect refined fusion systems to be able to come down in weight. Even if all the supporting infrastructure weighed more than the combination of bunker oil and diesel engine, it'd have to be a lot more to negate the advantages. As far as too complex, that really depends on the commercialization potential of fusion and how complex final designs are.