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Small nuclear reactors: tiny NuScale reactor gets safety approval

popularmechanics.com

211–220 of 554 posts

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#211

Earlier quoted context omitted.

You need a sufficiently large reserve to allow the reactor to cool, not an infinite supply. Reactors can be shut down and in this case the pool is sized to absorb all decay heat from the shutdown, plus a significant safety margin.

Great, and ideally gravity can be used to move it. Remember, at Fukushima power to the pumps was lost.

The reactor is submerged in the pool. It’s a passive design.

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#212

Earlier quoted context omitted.

This is IMO a positive for nuclear, not a negative. You're forced to confront the cleanup as opposed to fossil fuels, where you just blow your waste out into the atmosphere and make it the commons' problem.

If only a method for permanent disposal of nuclear waste actually existed.

It does. It’s called a breeder reactor.

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#213

Earlier quoted context omitted.

Nuclear power plants were designed with this in mind. It would take a substantially larger earthquake to damage a nuclear power plant and cause it to leak than a commercial pool. Such a comparison is in bad faith and disingenuous.

It's a people problem. People are fallible on the best days, assuming everyone did their very best from nuclear physicists to construction workers, mistakes are made. You take steps to reduce the risk. Research gets review. Engineering schematics get review. Construction gets inspection. Still some mistakes will get through. And people always act their very best all the time right? You can even have a perfect design,…

This. Humans are spectacularly bad at this kind of scale in time/project budget/size...

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#214

Thinking about the cooling pool: Could you just make an off-shore in-ocean "farm" of these?

Salt water might add to your corrosion issues. Also, physical security of nuclear reactors is a big deal. Now you need a navy to do it.

Half-kidding, and it wouldn't deal with the saltwater corrosion issues, but....

Legit use for Project Plowshare harbors?

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#215
post #73

Earlier quoted context omitted.

The idea is to put multiple reactors at the same site, not to spread out mini reactors all over the landscape. So the end result would be a powerplant that produces about as much power as a "normal" nuclear power plant, just that it contains many small reactors instead of a few big ones.

This undermines some of the claimed benefits. A bunch of little Fukushima Daiichi reactors in the same location wouldn't have fared any better than the actual Fukushima Daiichi reactor.

Uh, there are a bunch of reactors at Fukushima. It’s in the name: “daiichi” means “complex-1”, there is also a “daini”, etc.

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#216

Here 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…

The pool is big. It is easy to fill holes in the ground with water. In some parts of the country very hard to keep them dry.

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#217

Earlier quoted context omitted.

This is IMO a positive for nuclear, not a negative. You're forced to confront the cleanup as opposed to fossil fuels, where you just blow your waste out into the atmosphere and make it the commons' problem.

If only a method for permanent disposal of nuclear waste actually existed.

If only a method for permanent disposal of excess CO2 was viable.

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#218

Earlier quoted context omitted.

And so a pool of water is not enough because it will boil away. A continuous flow must be present that can not be interrupted.

You need a sufficiently large reserve to allow the reactor to cool, not an infinite supply. Reactors can be shut down and in this case the pool is sized to absorb all decay heat from the shutdown, plus a significant safety margin.

And if the pool gets a leak?

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#219

Earlier quoted context omitted.

This is IMO a positive for nuclear, not a negative. You're forced to confront the cleanup as opposed to fossil fuels, where you just blow your waste out into the atmosphere and make it the commons' problem.

If only a method for permanent disposal of nuclear waste actually existed.

SpaceX can launch it into space?

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#220
post #181

How is nuclear compatible with variable renewable energy sources? It can’t ramp up or down quickly, so it’s not good for filling the gaps in the day when the sun is not shining. And solar is now so cheap during sunny days that the excess power is curtailed or at a negative price.

Nuclear can operate in load following mode for a long time now. It's already done in Europe.

https://www.oecd-nea.org/nea-news/2011/29-2/nea-news-29-2-lo...

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