Small nuclear reactors: tiny NuScale reactor gets safety approval • Hacker News Board

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

#381

Post by manigandham » Fri, Sep 04, 2020, 5:39 AM UTC

pvaldes wrote: post #292

manigandham wrote: post #114

Earlier quoted context omitted.

We could dump it into the ocean and not worry about it. There's so much cooling capacity and radiation shielding in the oceans alone that we'd never run out of space, so all of the current disposal strategies are way above and beyond what's needed. Containment is solved problem. It's important to note that other energy types also produce waste. For example, coal ash is incredibly toxic and hard to dispose of, and we…

> We could dump it in the ocean and not worry about it This is the things that make me cringe when I see this people saying again "This time will be different, we promise". Look mum, radioactive tornadoes coming from the ocean...

What do you mean by this time? Nuclear waste has already been dumped in the oceans before (prior to new regulations). 8 nuclear submarines have been lost and there's no environmental impact detected.

This has been well studied by several groups including the US Navy, which is one of the biggest nuclear operators with over 80 reactors currently in warships. In the event of catastrophic loss, the plan is to just leave it because the oceans already have billions of tons of radioactive material and infinite capacity to absorb more.

Also nuclear reactors have occurred naturally [1] and without any serious fallout or contamination risks, showing that containment is really not that challenging. Most people think nuclear is scary because of popular science and culture, and they lack the knowledge and understanding to know any different. It's similar to people not trusting vaccines because they don't understand medical science.

1. https://blogs.scientificamerican.com/guest-blog/natures-nucl...

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

#382

Post by riffraff » Fri, Sep 04, 2020, 5:40 AM UTC

IgorPartola wrote: post #368

markvdb wrote: post #213

Earlier quoted context omitted.

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

We are scary good at it actually. For example check out this and think about the architects who started vs those who finished it: https://en.m.wikipedia.org/wiki/Florence_Cathedral

I am not sure something built by the catholic church, one of few institutions that lasted for the last 2k years, is the perfect example.

Unless we plan on getting the pope to build nuclear power plants, which does sound cool.

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

#383

Post by manigandham » Fri, Sep 04, 2020, 5:41 AM UTC

rstupek wrote: post #202

manigandham wrote: post #114

Earlier quoted context omitted.

We could dump it into the ocean and not worry about it. There's so much cooling capacity and radiation shielding in the oceans alone that we'd never run out of space, so all of the current disposal strategies are way above and beyond what's needed. Containment is solved problem. It's important to note that other energy types also produce waste. For example, coal ash is incredibly toxic and hard to dispose of, and we…

Or use the waste (which is still highly energetic) in a traveling wave reactor a la terrapower?

Yes, waste reduction through sustained reuse through different reactors is a good process. Eventually there will always be some waste to deal with though.

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

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Post by petre » Fri, Sep 04, 2020, 5:44 AM UTC

thekyle wrote: post #158

godelski wrote: post #150

Earlier quoted context omitted.

Nuclear sites are designed to withstand a strike from a commercial airliner (747). Like you, the designers imagined many of the events you mentioned and more. A good rule of thumb is that if you, a non-expert, can think of a scenario within 10 minutes, an expert has probably already thought of this scenario. Nuclear power plants and weapons sites have always been considered targets and thus considered extra scrutiny…

Wow. How do they design them to withstand a strike from a 747? That seems really difficult.

Yes. A NRC requirement for utility scale reactors after 9/11. One wonders why nuclear reactors are so expensive.

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

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Post by petre » Fri, Sep 04, 2020, 5:49 AM UTC

PeterStuer wrote: post #377

Fwiw, any nuclear reactor design in history was sold as 100% safe. In reality, shit happen. Contractors use subspec material, things on the building site get overlooked and inspectors miss things or get told to look away, But hey, I'm sure, this time, it will be different. 100%.

Watch the "A is for Atom" episode of Adam Curtis' Pandora's Box series. It's linked in one of my other comments. Basically industrialists and sales people got involved, brushing off scientists' concerns. And irresponsible politically connected engineers in the USSR. That's why we have Chernobyl and Fukushima.

However, these are lessons learned. Today it's quite hard to come up with a reactor design without many safeguards and passive safety features, like it's quite hard to come up with a car with no seatbelts or airbags.

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

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Post by ses1984 » Fri, Sep 04, 2020, 5:50 AM UTC

neltnerb wrote: post #321

ses1984 wrote: post #157

Earlier quoted context omitted.

There's no research being done on materials to safely contain molten radioactive salt, that research could be dangerous, pretty much only superpowers would have the resources to do the research.

Really? I literally read dozens of papers about it a decade ago, at least... I guess I don't work adjacent to there so maybe no one else does either. Odd, I never have heard a reason why they were all that much worse than alternatives other than for corrosion and licensing costs, I am surprised that such a well defined problem just stopped being studied. I suppose at some point it's not competitive with solar so what…

Ok, there probably is actually lots of research going on, what little I know of it is several years out of date by now, at the time, advocates for the tech complained about the lack of research being done and I took them at their word.

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

#387

Post by janmalec » Fri, Sep 04, 2020, 5:54 AM UTC

PeterStuer wrote: post #377

Fwiw, any nuclear reactor design in history was sold as 100% safe. In reality, shit happen. Contractors use subspec material, things on the building site get overlooked and inspectors miss things or get told to look away, But hey, I'm sure, this time, it will be different. 100%.

Nothing is 100% safe, who said Nuclear power is? Nuclear power always has been and still is one of the safest ways to generate electrical power and this is what counts. Solar power for example causes a lot of fatalities due to accidents that happen during installation and has it's own environmental problems, yet nobody talks about it.

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

#388

Post by kelnos » Fri, Sep 04, 2020, 6:09 AM UTC

godelski wrote: post #240

Klinky wrote: post #166

Earlier quoted context omitted.

You're underplaying the danger and overplaying the value. Who exactly is investing in this "green gold"? If it's so valuable why does no one actually want it, and why is the DoE stuck with half a trillion liability?

> Who exactly is investing in this "green gold"? France[0] > If it's so valuable why does no one actually want it, I mean France does... we actually gave them the tech. The reason we stopped is more political. But more people do this than just France, but they are the biggest example since 17% of their entire grid is powered from recycled nuclear. The other reason we don't do it is that it is just cheaper to buy more…

> 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.

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

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Post by jabl » Fri, Sep 04, 2020, 6:10 AM UTC

dheera wrote: post #271

ses1984 wrote: post #157

Earlier quoted context omitted.

There's no research being done on materials to safely contain molten radioactive salt, that research could be dangerous, pretty much only superpowers would have the resources to do the research.

> materials to safely contain molten radioactive salt Wouldn't a giant steel or stone vat work, in theory?

No, steel doesn't work, the salt is too corrosive. It's a very challenging problem, imagine you have half the periodic table floating around in a very radioactive salt at high temperature.

Early molten salt reactor experiments used Hastelloy N (nickel: 71 wt%, molybdenum:16 wt%, chromium: 7 wt%, iron: 5 wt%, others:1 wt%), which apparently works. But as others have noted, there is ongoing research to further improve it.

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

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Post by read_if_gay_ » Fri, Sep 04, 2020, 6:25 AM UTC

regularfry wrote: post #121

read_if_gay_ wrote: post #55

Earlier quoted context omitted.

That mini series is indeed a great watch but it's also not exactly factual.

Are there inaccuracies around the portrayal of why and how the reactor failed?

I don’t think there are fundamental inaccuracies about that, but there are many exaggerations about the immediate aftermath. E.g. the fireman’s hand burning from touching a graphite fragment stood out as a particularly egregious one. And it is in fact shown that the disaster was caused by incompetence and carelessness, which does support GGPs point.