Thinking about the cooling pool:
Could you just make an off-shore in-ocean "farm" of these?
Small nuclear reactors: tiny NuScale reactor gets safety approval
131–140 of 554 posts
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#132I was thinking Nuclear would be the stable baseline for renewable. But this is not a sustainable option. We need to enforce hydrogen. Do not submit to the fallacy of nuclear waste disposal. First Elon needs to fix space travel and make transport into the sun feasible. And we will have iter by then.
Hydrogen is not a good (at the moment at least) source of energy or fuel for cars or industry (chemically speaking, obviously much better together with Deuterium and Tritium for fission, though we are still from such a technology). Steam reforming, which is currently the most common way of hydrogen production, uses natural gas and water and produces plenty of CO2 [1]. Nice summary as for cars fuel application here [2].
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#133Earlier quoted context omitted.
>> What happens when the ultimate heat sink is lost? What's an example event where the ultimate heat sink might be lost?
Many inland rectors are built on waterways. A plant can shut down due to drought. That's a slow enough process that you have plenty of advance warning, though.
Some are built on man-made reservoirs held together with dams..
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#134Earlier quoted context omitted.
>> What happens when the ultimate heat sink is lost? What's an example event where the ultimate heat sink might be lost?
No expert, but if it's a pool of water then an earthquake might cause a leak?
You don't need to be an expert. Ask anyone who has owned an in-ground pool. Leaks are rare but do happen.
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#135Can someone refresh my memory?
Is generating electricity directly from the products of fission proven [mathematically] to be less efficient than
decay->steam->mechanical->electrical
or is just that the applied science of steam power is so far ahead of everything else?
My peace of mind would be much greater if the energy transfer went through solid state systems instead of a working fluid that is pretty good at carrying the bad products of a [malfunctioning] reactor.
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#136Earlier quoted context omitted.
If you could solve climate change for less than that, I think it would be splendid. To put that number in context, which is just an order of magnitude, it's $5,000 for every person on Earth, about 1.5x the current US national debt, and just under the combined market cap of NYSE+NASDAQ. As an existential problem for humanity that doesn't currently have a solution, I think that's a decent cost estimate.
Climate change his hardly an existential threat for humanity. We survived the last ice age with stone tools, this is a less severe change. Economic impacts from things like rising sea levels really depend on how much we spend on maintaining things as they currently are vs adapting to the new normal. Aka do you live below sea level, raise the city, or move somewhere else. https://en.wikipedia.org/wiki/Raising_of_Chica…
There's a very real risk that climate change could knock us back globally to a pre-agricultural level. If that happens, there's almost certainly no coming back: the only way we know how to get to our current level of civilization is by extracting substantially all the easily-extractable energy from the Earth's crust. We only get to do that once. This, today, could well be as good as it ever gets, for the only tree of life that we know for sure exists in the universe.
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#137Can someone refresh my memory? Is generating electricity directly from the products of fission proven [mathematically] to be less efficient than decay->steam->mechanical->electrical or is just that the applied science of steam power is so far ahead of everything else? My peace of mind would be much greater if the energy transfer went through solid state systems instead of a working fluid that is pretty good at carryi…
Has there even been a case of the steam being problematic?
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#138Here is the NRC website about this reactor: https://www.nrc.gov/reactors/new-reactors/smr/nuscale.html Here is an interesting sub-report: https://www.nrc.gov/docs/ML2022/ML20224A525.pdf Information withheld for security reasons. One item concerns the "ultimate heat sink". What happens when the ultimate heat sink is lost? Well a design assumption is that it is not lost: https://www.nrc.gov/docs/ML2020/ML20205L410.pdf…
Wasn't the big push (or maybe big PR push) for more research and development of Thorium reactors a few years ago because they fail closed/safely? That seems like the kind of thing you'd want for smaller reactors (which I assume means more and more geographically diverse, but don't really know).
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#139Earlier quoted context omitted.
I'm not an expert, but I'm not convinced about it reducing the need to maintain a nationwide grid. Nuclear reactors take ages to ramp up and down. It's basically going to be generating the same amount of power 24x7, but demand is going to fluctuate. The more other areas you're connected to, the more opportunity there is to send that power to someone who can use it. Obviously there's a law of diminishing returns at so…
> Nuclear reactors take ages to ramp up and down. Naval reactors are apparently very fast in this regard, so it's evidently not an inherent property of nuclear power. (The USN also has an unparalleled record of safely operating reactors; more that 5,000 reactor-years clocked without major incident.)
Does it count that a Navy man was killed at SL-1?
https://en.wikipedia.org/wiki/SL-1 https://www.findagrave.com/memorial/67718734/richard-carlton...
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#140Can someone refresh my memory? Is generating electricity directly from the products of fission proven [mathematically] to be less efficient than decay->steam->mechanical->electrical or is just that the applied science of steam power is so far ahead of everything else? My peace of mind would be much greater if the energy transfer went through solid state systems instead of a working fluid that is pretty good at carryi…
The problem is heat. fission produces a ton of it and it has to go somewhere. Yes, you can absorb radiation thrown off by fission, but you still have the problem that heat will melt everything.
So you throw water (or salt) on the reactor, heat it up, and do work with the steam that is ultimately produced.
It has less to do with steam being the ideal route and more to do the the practicality of dealing with heat.
AFAIK, most reactors are closed loops anyways, so there's not much of an issue with water carrying away radioactive materials.