Ultra Safe Nuclear • Hacker News Board

Re: Ultra Safe Nuclear

#241

Post by nine_k » Thu, Sep 17, 2020, 11:08 PM UTC

ajross wrote: post #237

hairytrog wrote: post #156

Two interesting things to see here, of many. They are really planning the sites to be temporary compared to the solar/wind/ and other industrial power plants that have little or no plan for returning their sites to the original virgin soil. And two, they seem to use a molten salt loop like in concentrated solar to meet variable demand without changing the power level of the reactor, which you can't really do because…

And unlike a natural gas plant, it costs 3-10x what the equivalent generating capacity in renewables would cost. I come to post this Same Thing every time this discussion comes up. It's not about safety. Everyone serious understand nuclear, even current technologies, is "safe enough" to be useful to build out. Nuclear is outrageously expensive , though. And new reactor designs don't seem to be making much progress on…

Two questions: (1) Night time. (2) Quiet time.

Of course there are batteries! But factoring them in seems to increase the cost significantly. Power lines and cross-continent smart grids are fine, too — but also not free to build and operate.

So a self-contained unit that does not depend on weather, does not need refueling, and includes its own energy accumulator has some appeal.

Re: Ultra Safe Nuclear

#242

Post by Teknoman117 » Thu, Sep 17, 2020, 11:10 PM UTC

phamilton wrote: post #235

jacobr1 wrote: post #197

Earlier quoted context omitted.

Ah, the the molten salt loop is like a flywheel?

My read is that it's somehow the inverse of a flywheel. A flywheel means consistent output for variable input whereas this is consistent input leading to variable output. Or maybe I'm way off.

That's my understanding as well. Rather than ramping the power output up or down with demand, you keep it at a constant power level and basically use the molten salt loop as a battery -> store energy when you're outputting more than is required, draw energy from it when you need more that you are producing.

The multi-gigawatt nuclear installations are typically supplemented by natural gas "peaker" plants to deal with higher demand than the reactor output, but lose any extra power produced.

If I recall correctly, the naval reactors (submarine and surface vessels) are the only ones that are designed to rapidly shift their power output.

Re: Ultra Safe Nuclear

#243

Post by Andrew_nenakhov » Thu, Sep 17, 2020, 11:13 PM UTC

socialdemocrat wrote: post #234

throwaway894345 wrote: post #121

Earlier quoted context omitted.

Critically, batteries aren't cost effective for the use case in question: storing solar and wind energy in a world where these are the primary energy sources. They're going down 5% per year, but who knows how long that trend will hold, especially if we're talking about a wide-scale switch to unreliable power sources (driving up the demand for batteries). I want to live in a world powered by solar and wind, but we can…

I have played around with a simulator for this. Wind and solar is so much cheaper than nuclear power that you can simple build a lot of overcapacity to deal with much of the storage issue. Wind almost never go to zero during a year. For the rest of the time you just use gas power plants. According to my calculations I could get lower kWh price than with nuclear and only provide 10-20% of the power from natural gas. W…

> Wind and solar is so much cheaper than nuclear power

Could you please cite a source for this extraordinary claim?

Re: Ultra Safe Nuclear

#244

Post by lucb1e » Thu, Sep 17, 2020, 11:14 PM UTC

jka wrote: post #24

grawprog wrote: post #8

So why has nuclear waste become a thing that's not mentioned anymore? It was a pretty big thing in the 90's, now it seems to get brushed under the rug for all this 'safe' nuclear power marketing. It's mot just meltdowns and containment breaches that are a problem with nuclear power. None of the renewable alternatives produce radioactive waste that needs to be stored and dealt with. https://en.m.wikipedia.org/wiki/Rad…

I don't know, and I have been wondering whether much of the evident pro-nuclear lobbying recently (it seems apparent on many threads here related to energy generation) might be due to the nuclear industry being in serious threat of becoming obsolete. I've harped on about this many times before, but the levelized cost of energy[1] for renewables like solar and wind power is substantially cheaper than nuclear power now…

I'm a little disappointed that the Levelized cost of energy link does not include, you know, the levelized cost of various energy sources.

Also, it doesn't include the number of hours needed to find and debate a place where you can actually put down renewables.

Places using the most power (those most densely populated, like the Netherlands where I come from) have enough space for nuclear reactors to keep the country running (if base load was all we needed; it's just for comparison). However, if we need to do it all renewable, we're going to be hard-pressed and perhaps dependent on other countries. It's always someone's back yard or a nature reserve and people are almost always going to protest it. Germany has certainly more space so it's not as if we need to bring it all the way up from Spain or even Africa, but is by no means as sparsely populated as the USA (232/km² in Germany vs 34/km² in the USA). The USA also gets way more sun than most of western Europe. I'm not saying "you have it all easy" but... you're definitely in an easier position to make it work.

Re: Ultra Safe Nuclear

#245

Post by layoutIfNeeded » Thu, Sep 17, 2020, 11:15 PM UTC

Wowfunhappy wrote: post #240

ajross wrote: post #237

Earlier quoted context omitted.

And unlike a natural gas plant, it costs 3-10x what the equivalent generating capacity in renewables would cost. I come to post this Same Thing every time this discussion comes up. It's not about safety. Everyone serious understand nuclear, even current technologies, is "safe enough" to be useful to build out. Nuclear is outrageously expensive , though. And new reactor designs don't seem to be making much progress on…

So, why did so many countries/companies originally build nuclear reactors, if the economics inherently don’t make sense? Has something changed?

Yes. Regulations.

Re: Ultra Safe Nuclear

#246

Post by dv_dt » Thu, Sep 17, 2020, 11:15 PM UTC

Wowfunhappy wrote: post #240

ajross wrote: post #237

Earlier quoted context omitted.

And unlike a natural gas plant, it costs 3-10x what the equivalent generating capacity in renewables would cost. I come to post this Same Thing every time this discussion comes up. It's not about safety. Everyone serious understand nuclear, even current technologies, is "safe enough" to be useful to build out. Nuclear is outrageously expensive , though. And new reactor designs don't seem to be making much progress on…

So, why did so many countries/companies originally build nuclear reactors, if the economics inherently don’t make sense? Has something changed?

I think a lot of countries built reactors when the economics of Nuclear reactors as well as the economics of renewables were unknown with respect what they would look like in scaled deployment. Modern looks at the operating costs vs time to build, vs modern construction practices from the US, France, China, et al seems say the economics of Nuclear reactors have stalled or increased, while the economics of renewables continue to make accelerating improvements.

Re: Ultra Safe Nuclear

#247

Post by Andrew_nenakhov » Thu, Sep 17, 2020, 11:16 PM UTC

ceilingcorner wrote: post #60

I find it a little odd that a site called Hacker News is so bullish on nuclear power. Could there be anything less hacker than a centralized, exclusively government owned and operated source of power? No thanks. I’d rather put more resources into solar, wind, and other sources of power that don’t depend on the government to not explode and irradiate the immediate area for hundreds of years.

Maybe it's because the more technical audience here is not as susceptible to fear-mongering efforts by anti-nuclear lobby.

Nuclear energy is the greenest and cleanest energy currently available to humanity.

Also, technical people like complex technology. In this regard nuclear power is very akin to space exploration and artificial intelligence.

Re: Ultra Safe Nuclear

#248

Post by littlestymaar » Thu, Sep 17, 2020, 11:18 PM UTC

hairytrog wrote: post #156

Two interesting things to see here, of many. They are really planning the sites to be temporary compared to the solar/wind/ and other industrial power plants that have little or no plan for returning their sites to the original virgin soil. And two, they seem to use a molten salt loop like in concentrated solar to meet variable demand without changing the power level of the reactor, which you can't really do because…

Excuse me, could you be more specific about why you think Xenon poisoning is relevant here? I think I just missed your point.

Re: Ultra Safe Nuclear

#249

Post by Baeocystin » Thu, Sep 17, 2020, 11:20 PM UTC

Wowfunhappy wrote: post #240

ajross wrote: post #237

Earlier quoted context omitted.

And unlike a natural gas plant, it costs 3-10x what the equivalent generating capacity in renewables would cost. I come to post this Same Thing every time this discussion comes up. It's not about safety. Everyone serious understand nuclear, even current technologies, is "safe enough" to be useful to build out. Nuclear is outrageously expensive , though. And new reactor designs don't seem to be making much progress on…

So, why did so many countries/companies originally build nuclear reactors, if the economics inherently don’t make sense? Has something changed?

The economics are what they are do to the legal burden and regulatory overhead more than the technology itself, at least here in the US.

Re: Ultra Safe Nuclear

#250

Post by Klinky » Thu, Sep 17, 2020, 11:20 PM UTC

wmf wrote: post #238

Klinky wrote: post #195

Earlier quoted context omitted.

Apples to oranges. Reactor designs are completely different. They are basically set it and forget it designs that then require extremely costly refueling and refurbishment. Edit: I was wrong, the Ultra Safe Nuclear plan is somewhat similar. My comparison was with typical power grid reactor designs, not disposable reactors like what's being proposed.

That sounds exactly like the submission we're (supposed to be) discussing.

You're actually right, in this case it is pretty comparable, so it's closer to apples to apples, which brings up concerns about costs and commercial viability of such a project, but that's not really point of this thread.