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Nuclear fission fuel is inexhaustible (2022)

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Re: Nuclear fission fuel is inexhaustible (2022)

#271

Post by codethief »

> Uranium could power the world as far into the future as we are today from the dawn of civilization—more than 10,000 years ago.

Thermodynamics would like to have a word:

> […] the Earth has only one mechanism for releasing heat to space, and that’s via (infrared) radiation. We understand the phenomenon perfectly well, and can predict the surface temperature of the planet as a function of how much energy the human race produces. The upshot is that at a 2.3% growth rate (conveniently chosen to represent a 10× increase every century), we would reach boiling temperature in about 400 years.

https://dothemath.ucsd.edu/2012/04/economist-meets-physicist...

Re: Nuclear fission fuel is inexhaustible (2022)

#272

Post by yellowapple »

ttfkam wrote: post #84
roenxi wrote: post #56

Earlier quoted context omitted.

> Edit: Really don't get the down vote here. It's costing the Japanese anywhere from $200-$800 billion? 1) That isn't an astronomical number. It is $2,000-$8,000 per Japanese person. For a freak accident. Put that in $/kWh terms and you might find that nuclear was reasonably cost effective even in one of the worst nuclear disasters in history, let alone under normal conditions. 2) I don't know if it is controversial;…

Pretty sure the cleanup costs for continued use of coal, oil, and natural gas due to global climate change far exceed any from nuclear, including even Chernobyl. Entire nations are disappearing under the rising seas [0]. So far they are relatively poor and lack political influence. Bangladesh is soon for the chopping block. Louisiana and Florida are not far behind. Folks really don't get how close to sea level massiv…

Also worth pointing out that there are plenty of low-lying inland areas both critical to the global economy and vulnerable to damage from climate change. Relevant to my own background: California's Central Valley sits pretty darn close to sea level, and is already dependent on rather elaborate levee systems to keep floodwaters and delta seawaters at bay. Said region produces large swaths of the world's entire supply of various fruits and vegetables; that farmland turning into ocean (a very real risk per various climate models) would be catastrophic for the global supply of said produce.

And that's just around sea level rise. The Central Valley's water issues are another probable symptom of global climate change, and just because the Valley lucked out with a wet winter this year doesn't mean that luck will persist. If push comes to shove, I'm sure California's agricultural sector would much rather invest the billions necessary for desalination and upgraded levees to address those symptoms than abandon California entirely - but those are still costs being thrust upon California due to a continued reliance on fossil fuels.

Re: Nuclear fission fuel is inexhaustible (2022)

#273

Post by mcpackieh »

sidewndr46 wrote: post #247
mcpackieh wrote: post #133

Earlier quoted context omitted.

I think you're confusing a few concepts here. Thermal-spectrum (slow neutron) nuclear reactors are much easier to control than fast reactors because they have much slower reaction times. But this isn't particularly relevant because thermal-spectrum supercritical water reactors are possible; supercritical water reactor doesn't implies fast reactor. Let's put fast reactors aside. In thermal-spectrum reactors, the moder…

I think what I was trying to convey was you can always undergo the scram action on a nuclear reactor to halt it. The problem with this is in some cases, this mean restarting the reactor costs more than the value of the electricity it will generate before refueling.

Well, you could scram a supercritical water reactor too. If there's an emergency that warrants scramming the reactor, the time it will need to restart should be low on your list of priorities.

As for refueling, in some designs like CANDU refueling can be done 'online', refueling one tube while the others are running.

Re: Nuclear fission fuel is inexhaustible (2022)

#274

Post by Detrytus »

effed3 wrote: post #233
Detrytus wrote: post #199

Earlier quoted context omitted.

Efficiency of solar and wind isn't the real issue. The problem is: solar only works during a day, and wind farms only work when there's wind. Which makes both of them irregular, unpredictable. It could be mitigated if we had a cheap mass energy storage technology, but we don't (Li-Ion batteries are way too expensive, and hydroelectric storage requires very specific conditions, it cannot be built just anywhere). What…

Yes, efficiency is not an issue, but is improving. Storage technology evolve, there are many battery technology, even better than li-ion if fully developed, and storage can be chemical, capturing co2 and making fuels with net zero CO2 pollution, can be thermal, can be even gravitational, hydrogen local storage, and energy can move in grids, to go where is need from where is available, engineering can do this now it t…

You make a lot of assumptions here, about the directions in which future technologies can possibly develop. The thing is: if we are making decisions right now, we should make it based on what we know for sure, not based on our hopes and dreams, which might never materialize. In 20 years time, if the technologies you mention do indeed appear, we can re-evaluate our approach.

> Uranium (like fossil fuels) is not everywhere, a shift of geopolitics will affect availability, sun and wind are everywhere, maybe not constant, but hardly vanish for long periods everywhere..

Sun disappears for half of the day, every day. Strong wind is not that common at all, except in few selected areas, like the seaside.

Re: Nuclear fission fuel is inexhaustible (2022)

#275

Post by mcpackieh »

chrisco255 wrote: post #223
mcpackieh wrote: post #192

Earlier quoted context omitted.

Uh, no. Only two thirds of petroleum used in America is used for transportation, and that includes all transportation. You cannot possibly get a 90+% reduction in petroleum use by electrifying all cars. https://www.eia.gov/energyexplained/oil-and-petroleum-produc...

So by that chart, a barrel of oil is basically 89% used to generate gasoline, distillate fuel oil (diesel), hydrocarbon gas, and jet fuel. That is to say, 89% is used for energy and 11% or less is used for plastic, asphault, and materials. That 27% industrial figure on the right chart includes things like propane production, which is mainly used as a heat source (nuclear could absolutely replace this). Either way, if…

You've got an interesting way of reading charts... are you classifying trains, trucks and boats all as cars? And classifying all process heat used in industry as "energy" is certainly true but you're abstracting away way too many details if you just suppose all of that can be replaced with electrical heating. A lot of process heat could be provided by very small nuclear reactors on site, but honestly that seems like a pipe dream.

Re: Nuclear fission fuel is inexhaustible (2022)

#276

Post by Detrytus »

Dah00n wrote: post #209
Detrytus wrote: post #199

Earlier quoted context omitted.

Efficiency of solar and wind isn't the real issue. The problem is: solar only works during a day, and wind farms only work when there's wind. Which makes both of them irregular, unpredictable. It could be mitigated if we had a cheap mass energy storage technology, but we don't (Li-Ion batteries are way too expensive, and hydroelectric storage requires very specific conditions, it cannot be built just anywhere). What…

If the storage facility is absolute safe against nature and current and future human stupidity and curiosity, yes.

guarding a single storage facility is easy: just put a thousand men with machine guns between it and anyone who could possibly try to raid it. Guarding against nature is even easier: we have at least a century worth of climate data, it's not that hard to select one place that is safe from earthquakes, hurricanes, and other disasters.

Re: Nuclear fission fuel is inexhaustible (2022)

#277

Post by skissane »

yawaramin wrote: post #270
skissane wrote: post #242

Earlier quoted context omitted.

Given an exajoule and a quad are close in value, you’d get roughly the same result with exajoules instead. Also, the fact that total US energy consumption is currently roughly 100 quads is only a passing coincidence - it would not have been true in the past and will not be true in the future. It is weird to justify choice of unit on the basis of a temporary coincidence in the data

The post is about a specific point in time, not for all time. So there's nothing wrong with taking advantage of a temporary alignment in the data.

> The post is about a specific point in time, not for all time. So there's nothing wrong with taking advantage of a temporary alignment in the data

The choice of quads as a unit was not made by the post author (John Walker), it was made by a US government agency (the EIA) and a US government-funded research lab (LLNL). Walker appears to have only chosen quads because of the use of quads by the convenient graphics those agencies have produced. The idea that they are using quads due to a “temporary alignment in the data” seems like a post hoc rationalisation - what unit were they using before this temporary alignment? Probably quads; and if not quads, then likely something else equally non-metric. It is unlikely the US government would have already been using SI units (or even a non-SI metric unit), then suddenly switch to a non-metric unit just because of a temporary alignment in the data; much more likely they use quads because that is the US government’s standard unit for this purpose, and already was long before this.

And to be clear, I’m not criticising Walker for choosing a convenient freely-usable graphic to illustrate his point, even if it is in weird units; I’m criticising the US government for its continued clinging to weird units like “quads” that almost nobody else in the world uses, when there is no good reason for them to do so.

Re: Nuclear fission fuel is inexhaustible (2022)

#278

Post by threeseed »

throwaway5959 wrote: post #240
pyrale wrote: post #147

Earlier quoted context omitted.

> The French managed to. I guess they have super-human engineering prowess. As a french Engineer, I can confirm this. For work inquiries, please reach me at pyrale@oversized.ego > The trick is that they keep building the same obsolete US-based design In fact, we don't keep building them. The last N4 reactor was delivered in 2003. Since then, aside from the failed joint-venture with Germany that is the EPR, France ess…

Why does it seem we can’t build complicated things like we used to? The same seems to be true here in the US as well.

You can. It's just not economical and sometimes politically tenable to do so.

Re: Nuclear fission fuel is inexhaustible (2022)

#279

Post by ben_w »

pfdietz wrote: post #256
ben_w wrote: post #128

Earlier quoted context omitted.

Sadly we don't get to ignore politics inconveniently making fission more expensive. If you do ignore politics and just look at costs alone, then we can make a global HVDC power grid for less than the cost of the other local upgrades we want regardless within each national power grid. People demand a safety standard from fission which is expensive, and keep demanding ever more safety from them, and when it can't do th…

The reason people demand higher standards is history. An example: stacks that scrub radioisotopes out of steam from confinement during serious accidents when the steam has to be released to prevent overpressurization of the confinement system. These were added to most European reactors after Chernobyl. The US and Japanese didn't add these, saying the cost wasn't worth it. Then Fukushima happened. Had the reactors the…

Given how few people got cancer from Fukushima, this doesn't really help make the fears seem rational.

One death from cancer, 2313 from relocating: https://ourworldindata.org/what-was-the-death-toll-from-cher...

Re: Nuclear fission fuel is inexhaustible (2022)

#280

Post by Ratalala »

codethief wrote: post #271

> Uranium could power the world as far into the future as we are today from the dawn of civilization—more than 10,000 years ago. Thermodynamics would like to have a word: > […] the Earth has only one mechanism for releasing heat to space, and that’s via (infrared) radiation. We understand the phenomenon perfectly well, and can predict the surface temperature of the planet as a function of how much energy the human ra…

Interesting read. I once wondered what would be the contribution to atmospheric heat of the combustion of cigarettes, and waved it as probably insignificant. A quick googling suggests burning a cigarette releases 7.8 J/mg of tobacco[1], that a cigarette weighs around 1 g, and that about 5 trillions (5e12) cigarettes are smoked annually [2]. This amounts to 3.9e16 J, or, averaged over one year, 1.2e9 W; corresponding to the total US energy consumption around 1730, according to the figure in parent's link.

Insignificant today, but not a few centuries back.

[1] https://www.researchgate.net/publication/307705601_Heat_Emis... [2] https://www.vitalstrategies.org/tobacco-atlas-global-tobacco...

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