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Nuclear fission fuel is inexhaustible (2022)

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Re: Nuclear fission fuel is inexhaustible (2022)

#91

Post by brazzy »

roenxi wrote: post #55
brazzy wrote: post #46

Earlier quoted context omitted.

It could very, very easily kill a thousand times more. That we haven't seen anything like a worst case scenario for a unclear accident does not mean those are impossible.

What do you think that worst case is, and how are you estimating it?

Core meltdown and containment failure in (or near and upwind of) a megacity would be the obvious one.

Another exciting option: unnoticed containment failure of waste storage, which contaminates huge amounts of groundwater over weeks and months before the contaminated water starts reaching a densely populated area.

And don't tell me these things can't happen outside the Soviet Union. Greed and complacenty can always find a way.

Re: Nuclear fission fuel is inexhaustible (2022)

#92

Post by abecedarius »

refurb wrote: post #33
bullen wrote: post #17

Maybe, but the heat added to earth has to be radiated away from earth. We have never added energy from matter at this scale before. Same for fusion.

Global energy production in 2019: 617 x 10^18 J Global energy from the sun per day : 430 x 10^18 J

Curious: for the latter I get 7e21 J, using Wikipedia's normal-insolation figure of 947 W and its Earth albedo of 0.3. That's an order of magnitude greater. I'm probably missing something, do you have a source?

(Of course my figure would only increase the difference you're pointing out.)

Re: Nuclear fission fuel is inexhaustible (2022)

#93

Post by effed3 »

zerodensity wrote: post #77
effed3 wrote: post #60

Earlier quoted context omitted.

>What does the future look like when we have 10 times as energy available? What does the future look like when we have 10 times the efficency on energy use? This is the right question/goal. Denemark (IIRC) has sometimes reached the 100% solar/wind coverage, sure in a sunny day and low demand situation, but 10 years ago this was unthinkable. This appear the true way of prosperity, not the growt of availability/consump…

Having excess energy is great! We can use it for alot of useful stuff. For example to: - Recycle waste products. Most (not all) things are recyclable you just need the energy. - Grow food vertically so more land can be nature. - Siphon greenhouse gasses out of the atmosphere. - Desalinate Water

About this i absolutely agree.. if there is an equal amount of wisdom.

Re: Nuclear fission fuel is inexhaustible (2022)

#94

Post by effed3 »

rayiner wrote: post #85
effed3 wrote: post #60

Earlier quoted context omitted.

>What does the future look like when we have 10 times as energy available? What does the future look like when we have 10 times the efficency on energy use? This is the right question/goal. Denemark (IIRC) has sometimes reached the 100% solar/wind coverage, sure in a sunny day and low demand situation, but 10 years ago this was unthinkable. This appear the true way of prosperity, not the growt of availability/consump…

> What does the future look like when we have 10 times the efficency on energy use Energy efficiency improvements of that magnitude don’t exist. In most industries, getting a 10% efficiency improvement would be groundbreaking. These are limits dictated by physics.

True, an overall 10% improvement is a big number, one order of magnitude is SF now. But for single technologies, more than 10% is possible, internal combustion engines vs electric, incandescent light vs led.. So reasoning on the global efficiency (resource and energy use, recycling of materials, capture of wasted energy, ) is the mainline to go. IN nature photosynthesis is around 100% efficient.

Re: Nuclear fission fuel is inexhaustible (2022)

#97

Post by dang »

eaasen wrote: post #30

[flagged]

"Please don't pick the most provocative thing in an article or post to complain about in the thread. Find something interesting to respond to instead."

"Eschew flamebait. Avoid generic tangents."

https://news.ycombinator.com/newsguidelines.html

Re: Nuclear fission fuel is inexhaustible (2022)

#98

Post by HPsquared »

SigmundA wrote: post #72
baybal2 wrote: post #47

Earlier quoted context omitted.

And important note that relatively modern coal and gas powerplants are more thermally efficient than nuclear. Nuclear is ran in between 250C-350C, which is rather inefficient, and requires very big turbines.

Nuclear does not emit carbon when used, the waste heat means very little, emissions are what matters when discussing efficiency. Plutonium 239 is also 83,610,000 MJ/kg vs coal at 35 MJ/kg so the difference in thermal efficiency is nearly meaningless given how much specific energy density advantage nuclear has.

That's why nuclear power has so much potential. We throw away >99% of it, we're barely scratching the surface.

Re: Nuclear fission fuel is inexhaustible (2022)

#99

Post by sidewndr46 »

baybal2 wrote: post #47
HPsquared wrote: post #27

Earlier quoted context omitted.

That chart overemphasizes waste heat. 1 MJ of heat at 50°C is a lot less valuable than 1 MJ of electricity. They are not interchangable. The 1 MJ of electricity could pump much more than 1 MJ of low-grade heat, and it would take a lot of low-grade heat to generate 1 MJ of electrical energy. The parameter of interest is exergy. That is, usable energy. https://en.m.wikipedia.org/wiki/Exergy

And important note that relatively modern coal and gas powerplants are more thermally efficient than nuclear. Nuclear is ran in between 250C-350C, which is rather inefficient, and requires very big turbines.

Isn't that a safety thing? To shutdown a natural gas plant you just close some valves feeding the facility, or at worse introduce something into the combustion path that halts combustion. Nuclear fission obviously can be moderated, but not in such a sharp and safe manner.
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