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Small nuclear reactors: tiny NuScale reactor gets safety approval

popularmechanics.com

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

#491

Post by runarberg »

valuearb wrote: post #488
runarberg wrote: post #485

Earlier quoted context omitted.

Dikes can also lead to the destruction of swamps or coastal habitat reducing natural ways of capturing the carbon. In some places they can also lead to further land corrosion which counterproductively will only increase flooding. So dikes are no way a silver bullet to protect lowlands from the effects of the climate disaster. Air conditioning does not protect workers that need to work outdoors, or people that live in…

You Malthusians have only been wrong for 300 years, be prepared to be wrong for a few hundred more. The world is awash in excess capacity.

It is very disingenuous of you to call me a Malthusian. The Malthusian theory sets a cap at population growth and predicts an inevitable scarcity driven famines and conflicts after a certain period of unhindered growth. It says nothing about the effects of real outside changes in the environment.

In fact these worries—and the fact that we are calling for drastic changes to prevent this disaster—is in fact counter to any Malthusian theory. A true Malthusian would state this collapse is inevitable. We state they are certain if we allow the climate disaster to progress unhindered.

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

#492

Post by sandworm101 »

i_am_proteus wrote: post #479
sandworm101 wrote: post #446

Earlier quoted context omitted.

So it requires gravity. It may seem trivial, but how would this thing react if suddenly not mounted vertically, say if it got knocked onto its side while running? Would coolant still flow as planned?

This is a great question! From reading the NRC submission, the support structure for the modules is Seismic Category 1 (rated for design basis earthquake). This includes the entire Reactor Building, its foundation, and requirements for the site on which it is built. The reactor building is also designed to withstand an impact from a large commercial aircraft. Note that conjecture that the modules are top-heavy appear…

Safety on the ground is one thing, the other is whether this sort of design might be used in less-than-earth gravity. We need passive/fail-safe reactors for space and this thing looks like it could fit inside a rocket.

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

#493

Post by sandworm101 »

torpfactory wrote: post #477
sandworm101 wrote: post #453

Earlier quoted context omitted.

They are vertical cylinders to be suspended vertically in a pool of water, not massive squat objects sitting on bedrock. They are thin and relatively top-heavy. It is not ludicrous to ask what could happen should they not remain as vertical as designed. From a planning perspective, if verticality is a requirement then that verticality has to be protected as strongly as any other aspect. Any attachment or mounting poi…

I think they are not trivial but relatively easy parts of the design. I’m sure they can design support structure to withstand whatever arbitrarily large earthquake you throw at it. The structure doesn’t need to be particularly light or compact so there shouldn’t be any design constraints getting in the way of strength. The heat transfer problem is much much harder and they’ve already solved that apparently.

I;m not saying it is impossible, just interesting. One option could be to suspend these reactors on cables from above. That might let them swing around all they want during even a huge quake. The water would act as the dampener. Not much extra engineering required.

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

#494

Post by mlindner »

Amazing how many people in this thread don't understand nuclear and are spouting rampant fear mongering. Nuclear is fundamentally a safe technology, and these new reactors are safer than anything before. Think about how many deaths have actually been caused because of nuclear compared to coal power. The difference is dramatic.

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

#495

Post by runarberg »

DanBC wrote: post #473
runarberg wrote: post #472

Earlier quoted context omitted.

Thank you for this correction. I guess there are in fact evidence for greater crop yield and more farmer profits with GMO crops. However this doesn’t really take away from my point that GMO didn’t fix world hunger. Farmers can save money by using less pesticide and have better crop yield all they want but that still doesn’t fix food not going to where it is needed. This—on its own—doesn’t even take away from my weake…

How do you feel about golden rice?

They have been growing golden rice for over 15 years now. And they have yet to deliver on the promise of providing the lacking nutrients to the people who need them.

I mean sure. If GMO can help people, sure go ahead and grow them. But the fact is that so far GMO crops are limited to large agriculture giants and is not used to help with the global food safety net. Particularly not for feeding the poorer parts of the world.

In addition, dietary vitamin A deficiency can easily be fixed now (as well as 20 years ago; and even 120 years ago) with better food distribution. We have been shipping food for millennia. We don’t need golden rice or any other GMO to fix this problem.

Just to clarify, I’m not against them researching and growing golden rice. I am against them lying about how this crop can save the world from a problem that can be already easily be fixed with existing methods.

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

#497

Post by gambiting »

Krasnol wrote: post #474
gambiting wrote: post #421

Earlier quoted context omitted.

Sure, but that's why I suggested deep borehole storage - there is no known geological process that can bring up material stored at 5km+ depth into the surface on any sort of human timescale. A mine, even at 700m depth, is just too shallow for long term storage.

But there are many human processes which can.

....and? If you wanted highly dangerous materials to use for some evil purposes it's 1000x easier to just manufacture some poison rather than dig 5km deep. I'd argue that making radioactive isotopes in an accelerator is still easier than digging. Not sure what your concern is here.

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

#498

Post by Klinky »

roenxi wrote: post #456
kelnos wrote: post #388

Earlier quoted context omitted.

> The other reason we don't do it is that it is just cheaper to buy more Uranium than setup reprocessing plants Is it cheaper to buy more Uranium and deal with the so-far-and-growing half-trillion dollar cleanup liability than to set up and operate reprocessing plants? Of course I wouldn't be surprised if that liability is considered "tomorrow's problem", so no one in power cares about it.

> I wouldn't be surprised if that liability is considered "tomorrow's problem", so no one in power cares about it. I was talking to an environmental scientist that other day who was lamenting that the liability for solar panel waste was being treated as "tomorrow's problem", and no one in power cares about it. If we factor in the tomorrow problem nuclear looks even better, because we have a chance of being able to de…

Solar does not have the special handling and proliferation issues that nuclear waste does. Disposing of or recycling broken solar panels is significantly less complicated than spent nuclear fuel and waste byproducts.

Recycling and disposal does need consideration for renewables, as well as nuclear. You cannot just say "Well no one is looking into it for solar, so nuclear should get a free pass too!", especially when nuclear waste is so much more hazardous. Also when considering the infrastructure costs associated with setting up proper reprocessing facilities, no it does not obviously come out ahead. It's incredibly expensive upfront.

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

#499

Post by p1mrx »

ses1984 wrote: post #442
p1mrx wrote: post #437

Earlier quoted context omitted.

There's a big difference between a dam and a pool; the pool is supported by the ground, and even if you bash holes in it, the water still has to find somewhere to go. Also, pools are not typically built from concrete and stainless steel. The safety requirement here is not "doesn't leak", it's "holds most of the water for 30 days (after which water is not required)". You would have to get an implausibly-large leak, du…

Is your intense short sightedness and complete lack of imagination actually the same quality or two different ones?

I don't lack imagination; my imagination just has enough structure to distinguish between realistic and unrealistic scenarios.

We should be orders of magnitude more worried about all the carbon dioxide we're dumping into the atmosphere, than the failure modes of an engineered hole in the ground.

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

#500

Post by p1mrx »

sandworm101 wrote: post #492
i_am_proteus wrote: post #479

Earlier quoted context omitted.

This is a great question! From reading the NRC submission, the support structure for the modules is Seismic Category 1 (rated for design basis earthquake). This includes the entire Reactor Building, its foundation, and requirements for the site on which it is built. The reactor building is also designed to withstand an impact from a large commercial aircraft. Note that conjecture that the modules are top-heavy appear…

Safety on the ground is one thing, the other is whether this sort of design might be used in less-than-earth gravity. We need passive/fail-safe reactors for space and this thing looks like it could fit inside a rocket.

One module weighs 762 tons, which is more than 10X the capacity of Falcon Heavy.
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