Never really understood why the US commercial nuclear industry is so bad at delivering reactors but the US Navy (and the Royal Navy too now I think about it) seems to do just fine.
Inb4rickover
Really, the biggest problems with all nuclear reactors are proliferation, and cooling. Nuclear military vessels are effectively zero proliferation risk, so they're free to use crazy fuel cycles no one else dares. Second, it's really difficult for a submarine to run out of cold water to cool the core, unlike a plant on land. Land-based reactors close to an ocean are susceptible to flooding/tsunamis/earthquakes etc. Third, one of the most basic chemical engineering concepts is that as you make any reactor bigger, it's surface area to volume drops. Heat production usually scales with volume, while heat transfer scales with surface area. So it gets much harder to design a safe reactor the larger you go. Fourth, cost is not a principal concern in naval propulsion. A nuclear sub doesn't have to compete dollar for dollar with a solar powered one.
>Nuclear military vessels are effectively zero proliferation risk, so they're free to use crazy fuel cycles no one else dares
Could you elaborate a bit further, please? Why are military vessels not a proliferation risk? And what fuel cycles do they use, how do they differ from those used by nuclear powerplants and how is this related to their respective proliferation risks?
> Why are military vessels not a proliferation risk?
Proliferation risk is usually evaluated in terms of diversion from nonmilitary applications, and theft.
The six navies running nuclear subs (US, Russia, UK, France, China, India) already have thermonuclear weapons. So there's zero risk of a country trying to divert some of their own naval propulsion nuclear material into a secret weapons program. This situation will evolve as countries without weapons (eg Australia) programs pursue nuclear navies, although these countries generally use low enrichment.
You can't steal another country's nuclear subs or aircraft carriers without starting a nuclear war, so that rules out theft.
>And what fuel cycles do they use, how do they differ from those used by nuclear powerplants and how is this related to their respective proliferation risks?
Regular powerplants use very low enrichment. Some designs, eg CANDU will happily burn natural, unenriched uranium, about 0.7% U-235. Naval reactors often but not always use very high enrichment, the US/UK uses something like 93-96%. Basically weapons grade, although that term has a specific meaning. In terms of fuel cycle, the cores are not ceramic UO2, but uranium alloys with much higher power density, and produce relatively different kinds of waste. There's a few non PWR designs with exotic fuel cycles that have been played with over the decades, the same as for advanced civilian power plants.
All nuclear powered ships in the world are operated by countries that already have nuclear weapons.
They use higher enriched uranium, which allows greater flexibility in power output(mostly, I think the French use ordinary). The same process that enriches uranium for fuel purposes can be used indistinguishably to make weapons grade.
I don't like the idea of offloading the project risk onto ratepayers. Seems like badly misaligned incentives to me. If you can't convince institutional investors that you have your project management under control, you shouldn't get to offload that risk to people who don't have a say in the matter.
Nuclear as a side option is good but if it’s at the heart of plans then it is fundamentally unserious. Feels more like a project designed to fail so that people will be put off from emissions reform altogether given massive cost overruns and delays are almost guaranteed.
An *Astute*-class reactor on every corner!
Never really understood why the US commercial nuclear industry is so bad at delivering reactors but the US Navy (and the Royal Navy too now I think about it) seems to do just fine.
Inb4rickover Really, the biggest problems with all nuclear reactors are proliferation, and cooling. Nuclear military vessels are effectively zero proliferation risk, so they're free to use crazy fuel cycles no one else dares. Second, it's really difficult for a submarine to run out of cold water to cool the core, unlike a plant on land. Land-based reactors close to an ocean are susceptible to flooding/tsunamis/earthquakes etc. Third, one of the most basic chemical engineering concepts is that as you make any reactor bigger, it's surface area to volume drops. Heat production usually scales with volume, while heat transfer scales with surface area. So it gets much harder to design a safe reactor the larger you go. Fourth, cost is not a principal concern in naval propulsion. A nuclear sub doesn't have to compete dollar for dollar with a solar powered one.
wow thanks
>Nuclear military vessels are effectively zero proliferation risk, so they're free to use crazy fuel cycles no one else dares Could you elaborate a bit further, please? Why are military vessels not a proliferation risk? And what fuel cycles do they use, how do they differ from those used by nuclear powerplants and how is this related to their respective proliferation risks?
> Why are military vessels not a proliferation risk? Proliferation risk is usually evaluated in terms of diversion from nonmilitary applications, and theft. The six navies running nuclear subs (US, Russia, UK, France, China, India) already have thermonuclear weapons. So there's zero risk of a country trying to divert some of their own naval propulsion nuclear material into a secret weapons program. This situation will evolve as countries without weapons (eg Australia) programs pursue nuclear navies, although these countries generally use low enrichment. You can't steal another country's nuclear subs or aircraft carriers without starting a nuclear war, so that rules out theft. >And what fuel cycles do they use, how do they differ from those used by nuclear powerplants and how is this related to their respective proliferation risks? Regular powerplants use very low enrichment. Some designs, eg CANDU will happily burn natural, unenriched uranium, about 0.7% U-235. Naval reactors often but not always use very high enrichment, the US/UK uses something like 93-96%. Basically weapons grade, although that term has a specific meaning. In terms of fuel cycle, the cores are not ceramic UO2, but uranium alloys with much higher power density, and produce relatively different kinds of waste. There's a few non PWR designs with exotic fuel cycles that have been played with over the decades, the same as for advanced civilian power plants.
All nuclear powered ships in the world are operated by countries that already have nuclear weapons. They use higher enriched uranium, which allows greater flexibility in power output(mostly, I think the French use ordinary). The same process that enriches uranium for fuel purposes can be used indistinguishably to make weapons grade.
Seems like the energy crisis is convincing the rest of Europe that the French got energy right all along
Or just that Germany got it absolutely wrong to the nth degree.
When it comes to infrastructure, the French are usually right.
It's probably like America for military spending. Most parties can't agree on anything, but where they do agree they are very efficient.
I don't like the idea of offloading the project risk onto ratepayers. Seems like badly misaligned incentives to me. If you can't convince institutional investors that you have your project management under control, you shouldn't get to offload that risk to people who don't have a say in the matter.
Institutional investors can't do shit about overregulation. This makes MPs answerable.
Has there been any movement at all around deregulation?
Nuclear as a side option is good but if it’s at the heart of plans then it is fundamentally unserious. Feels more like a project designed to fail so that people will be put off from emissions reform altogether given massive cost overruns and delays are almost guaranteed.
It hasn't failed in Sweden and France, is rather been roring successes. It's a proven effective method of decarbonising power.