4 ms·

I foresee fusion though, ultimately. I think it mostly solves the nuclear waste "problem" and should promise huge cheap energy, I'm excited by some outlandish t

I foresee fusion though, ultimately. I think it mostly solves the nuclear waste "problem" and should promise huge cheap energy, I'm excited by some outlandish things which could become feasible if electricity is truly cheap.

acidburnNSA 3y ago
What do you consider the biggest remaining challenge associated with the nuclear waste problem?
- reaperman 3y ago
  Personally, I think Yucca mountain is a great place to store it in the USA but that will likely never be politically viable. And I'm not sure what solutions exist for nations outside of North America. I'm also personally still concerned about transportation accidents resulting in permanently contaminated areas.
  - acidburnNSA 3y ago
    Outside the US, Finland's Onkalo repository is on track to be the first operational commercial repository [1]. We have some operating military ones, like WIPP already. [1] https://www.posiva.fi/en/index.html https://www.posiva.fi/en/index.html As for transportation, this has been a big concern for some time but has pretty rock-solid technical solutions [2]. We regularly ship high-level nuclear waste around (e.g. from nuclear submarines to Hanford) and haven't really had any incidents. I'd claim that the issue is basically solved with these robust containers. [2] https://www.youtube.com/watch?vW=hlextDSoVkQ https://www.youtube.com/watch?vW=hlextDSoVkQ
    - eru 3y ago
      For comparison, we have chemicals like mercury (and much worse) that stay dangerous forever, and we mostly handle them just fine. There's only a tiny amount of high level nuclear waste.
- zdragnar 3y ago
  There aren't technical problems, only political ones. Yucca mountain has been designated as the long term storage site since 1987 by Congress. Every change of party majority since then has either stopped or restarted work on it.
- icy_deadposts 3y ago
  Hanford has been consuming roughly 10% of the deparment of energy's annual budget for many years and is projected to continue to do so for decades. and the cleanup effort has been fraught with scary mishaps.
- xenadu02 3y ago
  Actinide burning reactors are IMHO a better path forward. There are various proposals and research reactors, some using alternate fuel cycles. The bottom line is the nastiest stuff in spent nuclear fuel are the actinides. They're all naturally radioactive and most of the stuff with long (10,000+ year) half lives that requires long-term storage. You need Yucca Mountain mostly for the actinides. If instead you smash them with fast neutrons you can get them to fission, releasing some energy (though sub-critical) and transmuting them into either much more stable isotopes (little radioactive decay) or really unstable ones (nasty but they decay so fast you only need to hold onto them for a few days/months/years). The short version is besides reprocessing spent fuel we should be putting the nasty stuff through the sausage grinder again to turn it into much less nasty stuff instead of fighting over where to keep the nasty stuff safe for 100,000 years.
kibwen 3y ago
I have good news: we have a working nuclear fusion reactor that produces power on the order of 300 septillion watts per second. In their wisdom, its engineers conveniently placed it about 1 AU from the Earth, meaning that all we need to do is catch the energy it's currently transmitting to us.
- FabHK 3y ago
  Presumably 300 septillion Watts (=Joule per second). And it's true that the sun shines about 100 PW, or 5000x humanity's total energy usage (≈20 TW) on the surface of earth on a nice day.
- quickthrower2 3y ago
  We are doing that more efficiently with higher levels of CO2
- weberer 3y ago
  And how would I go about that during Finnish winter?
  - pgeorgi 3y ago
    https://en.wikipedia.org/wiki/Synchronous_grid_of_Northern_Europe https://en.wikipedia.org/wiki/Synchronous_grid_of_Northern_E...
rgmerk 3y ago
Sure, it doesn't create long-lived waste, but it's a big stretch to assume that fusion reactors will be cheap. Even if you assume that the fusion part is cheap, you still have to convert the energy to electricity or at a minimum mechanical work (unless you're using the process heat, which is admittedly a possibility for a fair bit of current demand). Steam turbines aren't exactly cheap to build. Yes, there are alternative energy conversion possibilities for some possible fusion fuel cycles, but as I understand it those fuel cycles are much more difficult than D-T fusion and therefore are even further away from being a practical power source.

acidburnNSA 3y ago

What do you consider the biggest remaining challenge associated with the nuclear waste problem?

reaperman 3y ago
Personally, I think Yucca mountain is a great place to store it in the USA but that will likely never be politically viable. And I'm not sure what solutions exist for nations outside of North America. I'm also personally still concerned about transportation accidents resulting in permanently contaminated areas.
- acidburnNSA 3y ago
  Outside the US, Finland's Onkalo repository is on track to be the first operational commercial repository [1]. We have some operating military ones, like WIPP already. [1] https://www.posiva.fi/en/index.html https://www.posiva.fi/en/index.html As for transportation, this has been a big concern for some time but has pretty rock-solid technical solutions [2]. We regularly ship high-level nuclear waste around (e.g. from nuclear submarines to Hanford) and haven't really had any incidents. I'd claim that the issue is basically solved with these robust containers. [2] https://www.youtube.com/watch?vW=hlextDSoVkQ https://www.youtube.com/watch?vW=hlextDSoVkQ
  - eru 3y ago
    For comparison, we have chemicals like mercury (and much worse) that stay dangerous forever, and we mostly handle them just fine. There's only a tiny amount of high level nuclear waste.
zdragnar 3y ago
There aren't technical problems, only political ones. Yucca mountain has been designated as the long term storage site since 1987 by Congress. Every change of party majority since then has either stopped or restarted work on it.
icy_deadposts 3y ago
Hanford has been consuming roughly 10% of the deparment of energy's annual budget for many years and is projected to continue to do so for decades. and the cleanup effort has been fraught with scary mishaps.
xenadu02 3y ago
Actinide burning reactors are IMHO a better path forward. There are various proposals and research reactors, some using alternate fuel cycles. The bottom line is the nastiest stuff in spent nuclear fuel are the actinides. They're all naturally radioactive and most of the stuff with long (10,000+ year) half lives that requires long-term storage. You need Yucca Mountain mostly for the actinides. If instead you smash them with fast neutrons you can get them to fission, releasing some energy (though sub-critical) and transmuting them into either much more stable isotopes (little radioactive decay) or really unstable ones (nasty but they decay so fast you only need to hold onto them for a few days/months/years). The short version is besides reprocessing spent fuel we should be putting the nasty stuff through the sausage grinder again to turn it into much less nasty stuff instead of fighting over where to keep the nasty stuff safe for 100,000 years.

kibwen 3y ago

I have good news: we have a working nuclear fusion reactor that produces power on the order of 300 septillion watts per second. In their wisdom, its engineers conveniently placed it about 1 AU from the Earth, meaning that all we need to do is catch the energy it's currently transmitting to us.

FabHK 3y ago
Presumably 300 septillion Watts (=Joule per second). And it's true that the sun shines about 100 PW, or 5000x humanity's total energy usage (≈20 TW) on the surface of earth on a nice day.
quickthrower2 3y ago
We are doing that more efficiently with higher levels of CO2
weberer 3y ago
And how would I go about that during Finnish winter?
- pgeorgi 3y ago
  https://en.wikipedia.org/wiki/Synchronous_grid_of_Northern_Europe https://en.wikipedia.org/wiki/Synchronous_grid_of_Northern_E...

rgmerk 3y ago

Sure, it doesn't create long-lived waste, but it's a big stretch to assume that fusion reactors will be cheap. Even if you assume that the fusion part is cheap, you still have to convert the energy to electricity or at a minimum mechanical work (unless you're using the process heat, which is admittedly a possibility for a fair bit of current demand). Steam turbines aren't exactly cheap to build. Yes, there are alternative energy conversion possibilities for some possible fusion fuel cycles, but as I understand it those fuel cycles are much more difficult than D-T fusion and therefore are even further away from being a practical power source.