Ultra Safe Nuclear • Hacker News Board

Re: Ultra Safe Nuclear

#11

Post by rbecker » Thu, Sep 17, 2020, 3:40 PM UTC

3pt14159 wrote: post #7

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.

Deaths per joule are the lowest out of any major fuel source except for maybe wind, which is debatable depending on your assumptions about the future.

Sources on the deaths per joule claim:

https://www.nextbigfuture.com/2011/03/deaths-per-twh-by-ener...

https://energycentral.com/c/ec/deaths-nuclear-energy-compare...

Re: Ultra Safe Nuclear

#12

Post by SparkyMcUnicorn » Thu, Sep 17, 2020, 3:41 PM UTC

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…

They address how they deal with the radioactive waste in the video.

Re: Ultra Safe Nuclear

#13

Post by beefok » Thu, Sep 17, 2020, 3:43 PM UTC

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.

With the size constraint of that reactor (in volume), what's to say it would be used for the public? It could instead be the source of energy for a factory, or a data center for instance. I don't think we have to keep thinking about public use for these at all.

Re: Ultra Safe Nuclear

#14

Post by dangerface » Thu, Sep 17, 2020, 3:43 PM UTC

VBprogrammer wrote: post #4

I once wondered if it would be possible to have a nuclear power station which operated subcritically with extra neutrons injected from an outside source. The advantage I saw was that turning off the outside source would instantly stop the reaction, no worrying about articulating fuel rods and poison injectors. Unfortunately decay heat is still an issue. Turns out it's potentially a thing but has some technical challe…

As far as I know its not cost effective until the chain reaction starts so I don't think its possible to operate subcritically.

Thorium reactors can essentially do this safe shutdown as the fuel is a liquid rather than a solid so you can just dump the fuel and stop the reaction.

Re: Ultra Safe Nuclear

#15

Post by tyho » Thu, Sep 17, 2020, 3:43 PM UTC

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...

Re: Ultra Safe Nuclear

#16

Post by sambull » Thu, Sep 17, 2020, 3:44 PM UTC

teilo wrote: post #2

I'm all for the concept, but so far, everything I've seen has been nothing but concept.

Large awesome graphic page on the fuel, and how its super safe. Nothing about how they 'conceptualize' disposing of their waste.

Re: Ultra Safe Nuclear

#17

Post by manfredo » Thu, Sep 17, 2020, 3:45 PM UTC

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…

Because it's not a problem. There's actually very little of it. It occupies a volume the footprint of a football field and 10 yards high [1]. Storing it is pretty foolproof: bury it in an area with no aquifer. The main risk of contamination is getting into the groundwater. If there's no groundwater the risk of contamination is eliminated even if the containers decay over time. And lastly, it doesn't make sense to bury our waste right now because some of the latest reactors being built can use this waste as fuel.

We hold nuclear to an incredible double standard with respect to the waste it produces. Fossil fuels release substantially more radioactive waste [2], and that waste is poorly contained. Usually put in an exposed pile next to the plant, which occasionally spills into rivers nearby [3]. Not to mention a whole other host of pollutants like heavy metals, and the carbon dioxide that is th main driver of climate change.

1. https://www.energy.gov/ne/articles/5-fast-facts-about-spent-...

2. https://www.scientificamerican.com/article/coal-ash-is-more-...

3. https://en.m.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_f...

Re: Ultra Safe Nuclear

#18

Post by nimish » Thu, Sep 17, 2020, 3:45 PM UTC

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 with time alone. They depreciate faster as time goes on!

Investing in any such generator needs to be for other reasons like land scarcity.

Re: Ultra Safe Nuclear

#19

Post by gruez » Thu, Sep 17, 2020, 3:45 PM UTC

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…

>So why has nuclear waste become a thing that's not mentioned anymore

It's not? They specifically mentioned it about 1 minute into their "MMR Life Cycle" video in the linked page.

Re: Ultra Safe Nuclear

#20

Post by hindsightbias » Thu, Sep 17, 2020, 3:46 PM UTC

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…

The industry would prefer it be an unaddressed externality as there is no politically economical solution. So it’s assumed storage will always be local but not priced in.