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Yes, nuclear reactors are terrible as peakers. I think that they would make sense mostly to put a floor under worst-case-minimum scenarios for renewable power g

Yes, nuclear reactors are terrible as peakers. I think that they would make sense mostly to put a floor under worst-case-minimum scenarios for renewable power generation (like "a week-long period of intense winter cold, far from the equator, while wind isn't blowing much.") In that scenario, there would still need to be some long-duration storage system like hydrogen in salt caverns but the storage reserves don't need to be as large as in the 100% renewable scenario. The lower bound on daily generation is higher. Reactors would run at near-constant levels like now, the only difference being that they'd recharge storage systems at low-demand times. Or it could turn out that building very large storage systems, even capacious enough to e.g. ride through Germany's entire winter, is less expensive than building new reactors. I'm just trying to keep an open mind about a future role for new reactors. I'm pretty skeptical about starting new reactor builds right now. My strongest present opinion about power reactors is that it's a shame to close working units while their attached grids are still consuming fossil combustion power.

pfdietz 8y ago
The best case for nuclear in the future will be if new designs can reduce the levelized cost of energy to be more competitive with renewables. This requires new designs -- light water reactors can't do it. It will be a long shot in any case. I am favorable to Moltex's SSR, which uses molten salts but avoids some of the more vexing issues typical MSRs encounter. Small molten salt reactors might also address industrial process heat markets, where they'd have a possible advantage over renewable sources as their heat could be used directly.
- njarboe 8y ago
  "The best case for nuclear in the future" will be off Earth (I hope). High density portable energy sources are a godsend for solar system colonization. Solar and wind on Mars are much worse energy sources than on Earth, especially if you factor in the cost of transport. For a long time the most powerful system per kg is the one to use.
  - nradov 8y ago
    Launching them from the ground is a bit risky though. We can do it reasonably safely with RTGs but with complete nuclear reactors the risk of contamination in a crash is somewhat greater.
    - njarboe 8y ago
      Where did you get that information? A reactor that has never been run has almost no radioactivity. Its basically just native uranium metal/oxide. RTGs are a higher risk and more radioactive. It is really a shame that such wrong ideas are so widespread.

pfdietz 8y ago

The best case for nuclear in the future will be if new designs can reduce the levelized cost of energy to be more competitive with renewables. This requires new designs -- light water reactors can't do it. It will be a long shot in any case. I am favorable to Moltex's SSR, which uses molten salts but avoids some of the more vexing issues typical MSRs encounter. Small molten salt reactors might also address industrial process heat markets, where they'd have a possible advantage over renewable sources as their heat could be used directly.

njarboe 8y ago
"The best case for nuclear in the future" will be off Earth (I hope). High density portable energy sources are a godsend for solar system colonization. Solar and wind on Mars are much worse energy sources than on Earth, especially if you factor in the cost of transport. For a long time the most powerful system per kg is the one to use.
- nradov 8y ago
  Launching them from the ground is a bit risky though. We can do it reasonably safely with RTGs but with complete nuclear reactors the risk of contamination in a crash is somewhat greater.
  - njarboe 8y ago
    Where did you get that information? A reactor that has never been run has almost no radioactivity. Its basically just native uranium metal/oxide. RTGs are a higher risk and more radioactive. It is really a shame that such wrong ideas are so widespread.