4 ms·

> For most of the construction crew of such a reactor, that job is the first of that type in their career, and the last. They get trained on the job, and that

> For most of the construction crew of such a reactor, that job is the first of that type in their career, and the last. They get trained on the job, and that (ultra-expensive) training is then never used again. I am not disagreeing with the idea of Wright's law. The US Navy very likely benefits from it, but NuScale does not, and possibly never will. However, a) this does include other prices such site licenses and environmental assessment. b) Wrights law models a decrease with every doubling in units produced. At 1-2 a year, we're looking at a very long time to get several doublings in. NuScale meanwhile has 0 doublings under their belt. And NuScale is not alone in this field, there are dozens of companies, each one promising the same thing (SMNRs). The Navy has a single source for their reactors, NuScale has lots of competition and has to share the market, leading each of company to get even fewer reactors built per year. c) Someone has to pay those early costs. For the Navy, there are not many alternatives; there are no PV or Wind aircraft carriers. It's nuclear or oil. The same is not true about power generation. d) As you say, each navy reactor is about 3 NuScale modules. Why does the Navy not build 3 smaller modules and get even better scaling? Why not 30? I argue they don't because of the costs associated with horizontal scaling. NuScale meanwhile doesn't have a power budget they need to hit, they are trying to produce baseload power, and the bigger they make them the more economies of scale the nuclear reactor benefits from.

credit_guy 3y ago
> Why does the Navy not build 3 smaller modules and get even better scaling? That's a good point. Actually the Navy does build such smaller modules. The Navy uses 2 types of naval reactors, one for Virginia-class submarines, the S9G, which is very close to one NuScale module, and one for Ford-class carriers, the A1B, about 3 times larger. Each Ford-class carrier uses 2 A1B reactors. Why not 6 S9G? I don't know. But then why not a single reactor twice as large as an A1B? I don't know either. It looks like there are some tradeoffs. In any case, the fact that the Navy can build economically SMR-sized reactors is encouraging. Of course, the Navy can use technologies that are not available on the civilian market, for example their reactors use weapon-grade uranium. So it's not completely an apples-and-apples comparison. Still, NuScale has produced more than one million pages of documentation to get their SMR design approved by the NRC. One can imagine they also put a lot of thinking in the economic viability of the project. One way or another they convinced a large engineering, procurement and construction company (Fluor Corp) to buy them.
- _aavaa_ 3y ago
  > Still, NuScale has produced more than one million pages of documentation to get their SMR design approved by the NRC. One can imagine they also put a lot of thinking in the economic viability of the project. Just because the pile of sh*t is massive doesn’t mean there’s a pony somewhere underneath it.
  - credit_guy 3y ago
    You mean the docs they sent the NRC? That's not a pile of shit. The NRC is one of the most conservative regulatory bodies anywhere in the world, you can't send them garbage. Oklo tried that stunt and fell flat on their face [1]. [1] https://www.nrc.gov/reactors/new-reactors/large-lwr/col/aurora-oklo.html https://www.nrc.gov/reactors/new-reactors/large-lwr/col/auro...
    - _aavaa_ 3y ago
      No, I mean the economics. Oklo's issue was, and I quote, that they "repeatedly failed to provide substantive information [...] on the maximum credible accident (MCA) for the Aurora design, the safety classification of structures, systems, and components (SSCs), and other issues needed for the NRC staff to establish a schedule and complete its technical review." The NRC denied them, without prejudice might I add, a license based on an evaluation of the technical merits and safety of the reactor, not on its economics.
      - credit_guy 3y ago
        In that case you are right. I don't know what NuScale's economic argument was, and there's a (pretty good) chance that it will not work out. But, imagine that whenever you want a new car, the car company sent a crew to your house and builds the car in your backyard. All the parts needed will be shipped to your address, and workbenches, tools, machinery, too. They put the car together, paint it, dry it, and voila, the car is yours. Would it surprise you if it was 10 times more expensive than if it came from an assembly line?
Eggpants 3y ago
The Navy did try smaller modules but it turned out to be a major staffing and space issue. Having 30 modules/reactors on an aircraft carrier would require quite a bit more Nuclear trained sailors than 2 large modules/reactors. The oil storage space on old carriers turned into jet fuel storage. Having 30 reactors on the ship would definitely eat into that.

credit_guy 3y ago

> Why does the Navy not build 3 smaller modules and get even better scaling? That's a good point. Actually the Navy does build such smaller modules. The Navy uses 2 types of naval reactors, one for Virginia-class submarines, the S9G, which is very close to one NuScale module, and one for Ford-class carriers, the A1B, about 3 times larger. Each Ford-class carrier uses 2 A1B reactors. Why not 6 S9G? I don't know. But then why not a single reactor twice as large as an A1B? I don't know either. It looks like there are some tradeoffs. In any case, the fact that the Navy can build economically SMR-sized reactors is encouraging. Of course, the Navy can use technologies that are not available on the civilian market, for example their reactors use weapon-grade uranium. So it's not completely an apples-and-apples comparison. Still, NuScale has produced more than one million pages of documentation to get their SMR design approved by the NRC. One can imagine they also put a lot of thinking in the economic viability of the project. One way or another they convinced a large engineering, procurement and construction company (Fluor Corp) to buy them.

_aavaa_ 3y ago
> Still, NuScale has produced more than one million pages of documentation to get their SMR design approved by the NRC. One can imagine they also put a lot of thinking in the economic viability of the project. Just because the pile of sh*t is massive doesn’t mean there’s a pony somewhere underneath it.
- credit_guy 3y ago
  You mean the docs they sent the NRC? That's not a pile of shit. The NRC is one of the most conservative regulatory bodies anywhere in the world, you can't send them garbage. Oklo tried that stunt and fell flat on their face [1]. [1] https://www.nrc.gov/reactors/new-reactors/large-lwr/col/aurora-oklo.html https://www.nrc.gov/reactors/new-reactors/large-lwr/col/auro...
  - _aavaa_ 3y ago
    No, I mean the economics. Oklo's issue was, and I quote, that they "repeatedly failed to provide substantive information [...] on the maximum credible accident (MCA) for the Aurora design, the safety classification of structures, systems, and components (SSCs), and other issues needed for the NRC staff to establish a schedule and complete its technical review." The NRC denied them, without prejudice might I add, a license based on an evaluation of the technical merits and safety of the reactor, not on its economics.
    - credit_guy 3y ago
      In that case you are right. I don't know what NuScale's economic argument was, and there's a (pretty good) chance that it will not work out. But, imagine that whenever you want a new car, the car company sent a crew to your house and builds the car in your backyard. All the parts needed will be shipped to your address, and workbenches, tools, machinery, too. They put the car together, paint it, dry it, and voila, the car is yours. Would it surprise you if it was 10 times more expensive than if it came from an assembly line?

Eggpants 3y ago

The Navy did try smaller modules but it turned out to be a major staffing and space issue. Having 30 modules/reactors on an aircraft carrier would require quite a bit more Nuclear trained sailors than 2 large modules/reactors. The oil storage space on old carriers turned into jet fuel storage. Having 30 reactors on the ship would definitely eat into that.