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Ultra Safe Nuclear

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111–120 of 536 posts

Re: Ultra Safe Nuclear

#111
post #18

Safety is no longer the reason Nuclear is not worth it. The sun is a giant, free nuclear fusion plant in the sky. We can capture 1/5th of its output per square meter. For free! The wind -- caused by solar heating -- also generates free power. The cost of harvesting it is now so low, and will always continue to decline as any technology will, that any fuel-based generation mechanism is going to be rendered uneconomic…

The problem with these renewables over time is that their energy density is fundamentally limited compared to nuclear by physics. We need sustainable _ecologically_ friendly energy sources and at scale unfortunately density becomes all important. People can and will quickly point out the ecological nuclear disasters that have occurred. I only say this - be intellectually honest with yourself about those disaster zones _now_. Compare them to the alternatives and think about it. You will also point out - renewables are becoming much more efficient over time! This is true, but there is an enormous asymmetry in investment between renewables and nuclear, so to compare recent efficiency gains of renewables with the current status of nuclear seems unfair. From a purely theoretical level the energy density of nuclear gives many potential environmental benefits:

1. Less raw material: this has a huge impact on society as a whole. Solar panels and wind turbines require a lot of raw materials that must be mined, refined, transported and built on site. Nuclear requires these things too of course, but it is more energy dense - requiring less given similar levels of technological innovation.

2. Less space: I've seen solar panels go up in various institutions around where I live. They're awesome! But many times they replace what once were fields, forests or pasture land. Wind turbines are even worse, always altering the natural landscape. Do _not_ get me wrong - I fully support these renewables, but once again they are not as space efficient as nuclear at scale.

3. Less workers: purely an economic efficiency principle. At scale density matters with respect to cost effectiveness. Given the same innovation and investment as renewables, nuclear can bottom out in a cost effective way that could really reshape our current energy landscape. Renewables have a much higher threshold requiring a higher percentage of our overall economic output to be dedicated to them. This means many other initiatives (like - for example - many other innovations sorely needed to mitigate carbon emissions) simply won't have resources because our society has taken those resources up building less efficient renewables.

Re: Ultra Safe Nuclear

#112

Earlier quoted context omitted.

The glaring problem (pun intended) with solar and wind is that the sun doesn't always shine and the wind doesn't always blow and we don't have a good way to store energy for those sunless and windless intervals.

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.

The US has about 8 seconds worth of battery storage. By comparison, to use renewables for 80% of our electricity we would need 12 hours of energy storage. For 100%, 3 weeks of storage [1]. 1 hour of energy storage in the US is 500 GWh. This amounts to more than the sum total of global lithium iron battery production (currently about 300 GWh) [2].

1. https://pv-magazine-usa.com/2018/03/01/12-hours-energy-stora...

2. https://www.nextbigfuture.com/2020/02/world-battery-producti...

Re: Ultra Safe Nuclear

#113
post #63

Earlier quoted context omitted.

> put them on your roof, problem solved. This is why solar kills more people every year than nuclear, and your hydro storage and batteries are not even a drop in the ocean compared to total load or daily capacity of even a small grid.

Wha? Becuase stuff falls off your roof and kills them? How does that compare to tiles falling off your roof and killing people? This doesn't sound like a real thing. Hydro storage is quite literaly a drop in the ocean, get it.

No, because people installing solar routinely fall and die. Because of the low power density of renewables like wind and solar you need a lot of installation sites and constant maintenance of same, which means a lot of opportunities for people to have fatal accidents. Nuclear has the lowest death rate per joule of energy provided of any available power source.

Re: Ultra Safe Nuclear

#114
post #43

Earlier quoted context omitted.

How many deaths for Chernobyl, Three Mile Island and Fukushima? Would that number change your mind?

How many people with increased cancer rates from solar? Stop quoting deaths from nuclear accidents - the harm from nuclear incidents goes far beyond killing people outright.

Then how much harm? How many cancers?

Re: Ultra Safe Nuclear

#115
post #18

Safety is no longer the reason Nuclear is not worth it. The sun is a giant, free nuclear fusion plant in the sky. We can capture 1/5th of its output per square meter. For free! The wind -- caused by solar heating -- also generates free power. The cost of harvesting it is now so low, and will always continue to decline as any technology will, that any fuel-based generation mechanism is going to be rendered uneconomic…

>The sun is a giant, free nuclear fusion plant in the sky. We can capture 1/5th of its output per square meter. For free!

From the surface of the Earth we can capture 1/100000000000000000000000000th of its output per square meter, for $100.

That's because it's not really in the sky, as a bird or plane might be. It's 93 million miles away.

As a result hardly any light makes it to Earth over a small area. You need like $1000+ of paneling and many square meters to capture enough of it to operate a hairdrier electrically. Which makes sense because a hairdrier uses a lot more energy than drying your hair by standing in daylight. On a cool morning you'd start sniffling from cold before the sun dried your hair. No animal gets its energy from photosynthesis, they wait for stationary plants to do it over months and years and then eat them. The sun is just not that energetic seen from Earth.

So yes it is a 384.6 yottawatt nuclear power plant. But we're so far away we can get a hundred watts of it for $100, on a good day.

Could be cool to send something there to collect and ship us electricity in bundled form though.

Re: Ultra Safe Nuclear

#116
post #51

Earlier quoted context omitted.

First, point out that Chernobyl, 3 Mile Island, and Fukushima amount to extremely small numbers of deaths relative to the power these plants generated. For three mile island and Fukushima this figure is zero among the public. Less than two dozen among the plant workers (all of which died due to the hydrogen explosion not radiation). The areas that were evacuated are now safe to return. Chernobyl was worse, but th Sov…

> First, point out that Chernobyl, 3 Mile Island, and Fukushima amount to extremely small numbers of deaths relative to the power these plants generated. I keep seeing justifications like that and it makes me want to puke. First of all: The total number of victims is unknown and it is still rising. Even for Chernobyl. Second: It costs tens of billions of dollars to clean up these messes. Paid for by the cow you can m…

> I keep seeing justifications like that and it makes me want to puke

This kind of justification is _indeed_ a bit cynical and morbid. I suspect it is a way to respond to the sometimes overly emotional argument from nuclear opponents.

I don't think it helps having a cool-headed debate on this complicated topic.

However, I do think mentionning that all form of electricy productions have risk trade-offs, and illustrating it with the insane number of casualties caused by other sources of energy production is relevant. (Eg: https://www.statista.com/statistics/494425/death-rate-worldw...)

But a bit of "tact" is warranted.

> First of all: The total number of victims is unknown and it is still rising. Even for Chernobyl.

The total number of victims from the direct events (explosion, short term exposure) is largely "known" (although the Soviet numbers might not be trustworthy, if you want to go this direction.)

The long-term numbers are of course harder to estimate. Again, it's going to sound morbid; but, to know if it's "still rising", you have to determine if someone who dies from a cancer 34 years after the event died because of the event.

I'm in no way qualified to say so.

I have to revert to the same method I use when I don't know stuff: I find scientists to trust.

In this case, the UN organization that has to investigate such things does not see a massive hidden mortality, as I understand it. (https://www.unscear.org/unscear/en/chernobyl.html#Exposure .)

It is entirely possible not to trust UN on this, but not really helpful.

> Second: It costs tens of billions of dollars to clean up these messes. Paid for by the cow you can milk forever: tax payers.

That's absolutely true. It's also the tax payers who invested money to build the plant, and reap the benefit of having the energy. Again, this is a cost-benefit analysis. It's perfectly possible to not come to the same conclusion depending on your level of risk averseness.

However here, again, it's not irrelevant to mention that all sources have this kind of trade-off.

And, to put it bluntly, I assume it would also be the tax payer would who have to clean-up after a broken dam. Or an hydrogen storage tank that explodes. Or burying the child mining the rare-earths needed for solar panels. Or curing the respiratory diseases caused by fossil fuels as we speak. Not even mentioning the various climate events.

> In short, if the goal is decarbonization wind and solar are the only game in town. Add medium and long-term storage to the mix and there's nothing stopping us from a truly green future other than politics.

Unfortunately, the `medium` and `long-term` storage does not seem to exist yet at the scale required to sustain modern world grids - at least according to scientists who would like to decarbonize just a much as you and I. (https://www.sciencemag.org/news/2018/03/meet-vaclav-smil-man... , https://jancovici.com/transition-energetique/renouvelables/1...)

I would love the situation to be more simple. The same science that tells us the climate is changing it telling us our energy situation is not easy to solve - yet.

In the meantime, we'll have to use all tools available (including the dangerous but efficient ones.)

I'm in no way an "absolute fan" of current nuclear (Although I'm much more concerned about the long term storage of waste - not so much because it's dangerous, but because no one wants it in their backyard. And proliferation, a bit.)

I'm all for investing in doing nuclear fission differently. If the design presented here does lower the risk of accident, as they claim, that would be for the best.

I don't think you're trusting the claim, and I can say that I'm rather skeptical too - but mostly because I don't know much. If enough scientist tell me this kind of nuclear plant is safer, I can accept that.

----

Off-topic: If I was very cynical and very pro-nuclear, I would fund a massive superproduction about a giant dam collapsing. The super-vilain could be a corrupt entrepreneur helped by an ambitous greenwashing politician.

Re: Ultra Safe Nuclear

#117
post #53

Earlier quoted context omitted.

That is extremely unlikely. You need to cover single digit percentages of the world with solar panels (depending on latitude) to cover all our energy needs.

What about our energy needs several decades from now? Falling prices make new applications possible which raises demand.

There are still more than enough deserts that we could fill with solar panels.

Re: Ultra Safe Nuclear

#118
post #15

The walk away passive safety is a tradeoff with non-proliferation concerns. This design requires 20% enrichment, much higher than traditional reactors. This might be a smart tradeoff, but let's not pretend it's doesn't exist. https://www.aps.org/units/fps/newsletters/201810/reactors.cf...

The countries in the nuclear club represent a significant fraction of the world's energy consumption. Even if they were the only ones to eliminate the use of carbon-based energy via nuclear, it would be a good start.

Re: Ultra Safe Nuclear

#119
post #82

Earlier quoted context omitted.

The fuel in fact doesn't come from the Sun, but from other stars that went super nova before the solar system was formed. Normal fusion in stars in not hot enough to produce such heavy elements.

Thanks, I didn't know that I thought it was like the rest.

You may find this chart interesting: https://en.wikipedia.org/wiki/Stellar_nucleosynthesis#/media...

Re: Ultra Safe Nuclear

#120
post #18

Safety is no longer the reason Nuclear is not worth it. The sun is a giant, free nuclear fusion plant in the sky. We can capture 1/5th of its output per square meter. For free! The wind -- caused by solar heating -- also generates free power. The cost of harvesting it is now so low, and will always continue to decline as any technology will, that any fuel-based generation mechanism is going to be rendered uneconomic…

The sun and wind are both very low energy density, and are intermittent sources. The sun is only available for part of the day, and wind is highly variable in a short term time frame. The real cost of using renewables for a primary source of energy is the cost of storage. Using renewables for 80% of our energy demand would require 12 weeks of storage - to get to 100% it would take 3 weeks of storage [1]. These are st…

what about cultural changes ? serious question. less living at night, less energy consumption, making sun randomness a bit less of an issue. Just asking.
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