3 ms·

Just a FYI that article you linked is written by someone that doesn’t actually understand what’s going on they even say: “I‘m a little fuzzy on the economic mod

by Retric 2y ago

Just a FYI that article you linked is written by someone that doesn’t actually understand what’s going on they even say: “I‘m a little fuzzy on the economic model, but” And then say things that aren’t true. The baseline cost of fuel rods alone ends up being ~0.9c/kWh. That already significantly eats into the margins before you consider the ~500 person workforce required to maintain such a complex system 24/7 365. The physical degradation of equipment like pumps, turbines, and lightbulbs costs yet more money. Decommissioning again yet more costs. People focus on the upfront construction costs because they are extreme, but even if construction costs were the same as a coal power plant nuclear electricity would still be quite expensive. Further, many things like the initial fuel supply get lumped under ‘construction costs’ but are better thought of as something else like operating expenses.

roenxi 2y ago
It is an argument based mainly on learning rates. He doesn't need to know any details about the economic model of nuclear; the observations are based on the economic model changing over time. > The baseline cost of fuel rods alone ends up being ~0.9c/kWh. I saw a quote from the 4th generation reactor wiki page (it came up while people were talking about China getting started on the build out of next gen of nuclear tech) that mentioned "100–300x energy yield from the same amount of nuclear fuel" as a potential advantage. People will figure out how to make fuel rods cheaper. We haven't really pushed the limits of this stuff. Besides, even in the current climate 1c/kWh is still a great lower bound to aspire for. Possibly even that would be worth pushing through the political blowback for.
- Retric 2y ago
  Gen IV doesn’t mean anything specifically. No individual gen IV designs has every single advantage you see in any of those designs. You need to look at a specific designs in isolation as well as what trade offs are involved in that design. “100-300x energy yield from the same amount of nuclear fuel” That’s one of those things that sounds good in isolation, but ends up being more expensive. It’s just like CANDU reactors don’t need enrichment and can operate on natural uranium, but it turns out fuel costs drop by 20% when they started enriching the fuel. Similarly LWR/HWR could make better use of their fuel if they could operate at higher temperatures, but that causes a world of other problems. Unfortunately nuclear engineers aren’t dumb, they’re doing things for surprisingly solid reasons even if counter intuitive reasons.
kragen 2y ago
i'm not convinced that the fuel is inherently that expensive; plausibly a lot of that cost is unnecessary bureaucracy and antiproliferation costs. i think the killer is your point, 'even if construction costs were the same as a coal power plant'
- Retric 2y ago
  Again when you dig into things some things are inherently extremely expensive like operating a lot of gas diffusion centrifuges. You could cut fuel use in half if the thermal efficiency of nuclear increased to that of a combined cycle coal power plant. But having two water loops (or a liquid salt then water etc) inherently reduces the temperatures the second loop reaches compared to the primary loop. On top of this you want to stay well away from material limits for safety concerns. Net result the maximum Carnot efficiency is only like 45% and achieved efficiency is significantly lower than that.
  - kragen 2y ago
    gas diffusion centrifuges are an excellent example; possibly, for example, silex will turn out to be orders of magnitude cheaper. the absolute thermodynamic limit for isotope separation is many orders of magnitude away from what is currently practiced. and of course if you run your reactors on thorium or plutonium you don't need isotope separation interesting, i hadn't heard of igcc before. thanks!
    - deleted 2y ago
      [deleted]
    - Retric 2y ago
      Yea, I don’t think things are hopeless here. What you mention might drop fuel costs by as much as 0.3c/kWh which would be a major step forward, but nuclear needs several such wins and it needs them quickly. People aren’t going to ramp up construction until the economics change significantly and then you’re looking 6+ years out before anything comes online. Meanwhile investors are thinking what will renewables look like in 6-60 years from now? which makes such projects hard to justify without massive subsidies or at minimum locked in pricing for decades.

by Retric 2y ago

roenxi 2y ago

It is an argument based mainly on learning rates. He doesn't need to know any details about the economic model of nuclear; the observations are based on the economic model changing over time. > The baseline cost of fuel rods alone ends up being ~0.9c/kWh. I saw a quote from the 4th generation reactor wiki page (it came up while people were talking about China getting started on the build out of next gen of nuclear tech) that mentioned "100–300x energy yield from the same amount of nuclear fuel" as a potential advantage. People will figure out how to make fuel rods cheaper. We haven't really pushed the limits of this stuff. Besides, even in the current climate 1c/kWh is still a great lower bound to aspire for. Possibly even that would be worth pushing through the political blowback for.

Retric 2y ago
Gen IV doesn’t mean anything specifically. No individual gen IV designs has every single advantage you see in any of those designs. You need to look at a specific designs in isolation as well as what trade offs are involved in that design. “100-300x energy yield from the same amount of nuclear fuel” That’s one of those things that sounds good in isolation, but ends up being more expensive. It’s just like CANDU reactors don’t need enrichment and can operate on natural uranium, but it turns out fuel costs drop by 20% when they started enriching the fuel. Similarly LWR/HWR could make better use of their fuel if they could operate at higher temperatures, but that causes a world of other problems. Unfortunately nuclear engineers aren’t dumb, they’re doing things for surprisingly solid reasons even if counter intuitive reasons.

kragen 2y ago

i'm not convinced that the fuel is inherently that expensive; plausibly a lot of that cost is unnecessary bureaucracy and antiproliferation costs. i think the killer is your point, 'even if construction costs were the same as a coal power plant'

Retric 2y ago
Again when you dig into things some things are inherently extremely expensive like operating a lot of gas diffusion centrifuges. You could cut fuel use in half if the thermal efficiency of nuclear increased to that of a combined cycle coal power plant. But having two water loops (or a liquid salt then water etc) inherently reduces the temperatures the second loop reaches compared to the primary loop. On top of this you want to stay well away from material limits for safety concerns. Net result the maximum Carnot efficiency is only like 45% and achieved efficiency is significantly lower than that.
- kragen 2y ago
  gas diffusion centrifuges are an excellent example; possibly, for example, silex will turn out to be orders of magnitude cheaper. the absolute thermodynamic limit for isotope separation is many orders of magnitude away from what is currently practiced. and of course if you run your reactors on thorium or plutonium you don't need isotope separation interesting, i hadn't heard of igcc before. thanks!
  - deleted 2y ago
    [deleted]
  - Retric 2y ago
    Yea, I don’t think things are hopeless here. What you mention might drop fuel costs by as much as 0.3c/kWh which would be a major step forward, but nuclear needs several such wins and it needs them quickly. People aren’t going to ramp up construction until the economics change significantly and then you’re looking 6+ years out before anything comes online. Meanwhile investors are thinking what will renewables look like in 6-60 years from now? which makes such projects hard to justify without massive subsidies or at minimum locked in pricing for decades.