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Ultra Safe Nuclear

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Re: Ultra Safe Nuclear

#231

Post by lmilcin »

cbmuser wrote: post #210
lmilcin wrote: post #155

Earlier quoted context omitted.

Yeah, exactly. Even though it is costly to deal with, per kilogram, there is very little of it when compared to amount of energy produced. An atomic plant might use couple dozen tonnes of fuel which is peanuts compared to the amount of waste from coal power plant. There are no technical problems with storage that we can't solve. The biggest problem is that nobody wants it around.

Even without considering the amount of energy produced, it’s nothing. The US has accumulated 83.000 tons in decades. Compare that to the billions of tons CO2 that coal plants blow into the atmosphere.

Coal plants do not just blow CO2 into the atmosphere. What is left after burning coal is highly toxic and does not degrade.

https://en.wikipedia.org/wiki/Health_effects_of_coal_ash

Though, I agree CO2 is bigger problem. Unless you just bought property in Greenland and wait for it to live up to its name.

Re: Ultra Safe Nuclear

#232

Post by rwcarlsen »

sbierwagen wrote: post #214
theptip wrote: post #196

Earlier quoted context omitted.

One point that's commonly missed in the lay discussions is that the stuff with a really long half-life (e.g. uranium/plutonium) is not that radioactive/harmful; by definition if it takes you 100k years for 50% of your unstable nuclei to decay, the emission rate per second is very low. In contrast, the really nasty stuff has a very short half-life, and emits radiation at a very high rate for a very short duration. The…

>do something safe with the potentially weapons-grade plutonium Reprocessed plutonium from a civilian power reactor would never be weapons-grade, it has too much Pu-240 in it: https://en.wikipedia.org/wiki/Reactor-grade_plutonium It is claimed that it is possible to make weapons from reprocessed plutonium, but the warheads would need active cooling and exotic pit geometries, making them not so amendable to miniaturiz…

It looks like you replied to the wrong sibling comment.

Re: Ultra Safe Nuclear

#233

Post by Udik »

xibalba wrote: post #3

Assuming nuclear truly can be ultra safe, how do you convince a public that has seen Chernobyl, Three Mile Island, and Fukushima to get on board? Particularly when the "competition" (solar, wind, etc) has such a strong tailwind.

Just ask people if they think climate change is an existential threat. If they answer yes (as will most people who are opposed to nuclear energy) then ask them if they think nuclear energy is an existential threat too or just extremely dangerous.

If the answer is "just extremely dangerous" then the choice is simple. Actually, I can't understand why all those who are predicting doomsday scenarios because of climate change aren't storming the streets with big pro-nuclear energy signs.

Re: Ultra Safe Nuclear

#234

Post by socialdemocrat »

throwaway894345 wrote: post #121
mdorazio wrote: post #54

Earlier quoted context omitted.

We do have a good way to store energy. It's called batteries, they are already cost effective in several use cases, and their cost is going down about 5% per year.

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.

We can run on 10-20% natural gas for a while until we develop better storage.

Re: Ultra Safe Nuclear

#235

Post by phamilton »

jacobr1 wrote: post #197
hairytrog wrote: post #189

Earlier quoted context omitted.

I highly recommend HBO's Chernobyl. Explains a lot this stuff. Basically, as a nuclear reactor operates, it is turning the Uranium into lots of other stuff. One component of this other stuff is Xenon-135, which absorbs neutrons and basically gets in the way of nuclear reactions. This is not an issue if you keep the reactor on because there are enough neutrons to keep things going and overcome the Xenon absorption. Bu…

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.

Re: Ultra Safe Nuclear

#236

Post by sbierwagen »

rwcarlsen wrote: post #232
sbierwagen wrote: post #214

Earlier quoted context omitted.

>do something safe with the potentially weapons-grade plutonium Reprocessed plutonium from a civilian power reactor would never be weapons-grade, it has too much Pu-240 in it: https://en.wikipedia.org/wiki/Reactor-grade_plutonium It is claimed that it is possible to make weapons from reprocessed plutonium, but the warheads would need active cooling and exotic pit geometries, making them not so amendable to miniaturiz…

It looks like you replied to the wrong sibling comment.

I have edited my comment to make it clearer which sentence I was replying to.

Re: Ultra Safe Nuclear

#237

Post by ajross »

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 that.

Look, I think nuclear is fine. But as a numerate and earnest environmentalist, I don't see where the case for it lies. Right now, we should be building out solar and wind as fast as we can, because they're good and safe and CHEAP. And when we get to that last 5-10% where we need buffering capacity that we're currently getting via gas? Yeah, maybe then we can talk about nuclear.

But even then... meh. What's the case on trying to finish the job on electrical generation vs. putting those same dollars into low hanging fruit in other areas of the energy puzzle?

Nuclear needs to make its case on a balance sheet before it makes sense to talk about.

Re: Ultra Safe Nuclear

#238

Post by wmf »

Klinky wrote: post #195
rurounijones wrote: post #103

Earlier quoted context omitted.

The US Navy has been successfully operating Nuclear Reactors without incident for decades in the harshest environments on earth [1] It can be done safely. https://www.mofa.go.jp/region/n-america/us/security/fact0604...

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.

Re: Ultra Safe Nuclear

#239

Post by Andrew_nenakhov »

socialdemocrat wrote: post #229
shakezula wrote: post #122

Earlier quoted context omitted.

Nuclear is the only way we’re going to be able to get ahead of climate change. Renewables do not have the energy density required at this point. In the 70s? Sure, we might have been able to get ahead of it. At this point, we’re going to need nuclear whether we like it or not. Nuclear is the only option that will provide enough power to both scrub out existing carbon from the atmosphere and reduce our output of carbon…

50m2 Solar on the roof top of every household would power An average western country. That is not a lot. And that is is an upper band as we have wind power, biomass, hydro power geothermal and many other sources of clean energy. Offshore wind is getting really cheap and offers vast amount of unused space.

There are western countries with snow in the winter. Also, countries where the majority of population lives in apartments.

Also, how would an average western country power itself at nights, if all it has is 50m2 solar on every roof top?

Re: Ultra Safe Nuclear

#240

Post by Wowfunhappy »

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…

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