Comment by lucb1e | Hacker News Reader

Comment by lucb1e | Hacker News Reader

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I wonder if this is correct. Setting the nuclear slider to max single-handedly reduces emissions by 30%, decreases energy costs rather than increases, does not require land use change, improves air quality, and also reduces electricity demand by using the waste heat for district heating.

Now add: (1.) electrification of freight transport, (2.) tackling the (relatively) quick wins in industry electrification, and (3.) carbon capture, and one gets to 75% emissions reduction with less than one percent of cost increase and zero behavioural changes (such as eating less meat or flying less often) are required.

I can't find any other combination in this calculator that leaves nature so untouched, requires so little land use, requires no behaviour adjustment, or is so cheap while still reducing emissions meaningfully. (Well, geothermal is nearly as good but then its maximum potential is only a small percentage of energy demand and it's also a bit more expensive per Joule.)

Probably the most unrealistic part is public support for the choice, but in a perfect world? Would it be this simple?!

This is strange considering nuclear continues to be the most expensive new form of fuel and has only been getting more expensive with every passing decade.

There is new research in nuclear which if successful would bring costs down but it’s hard to see how maxing out on nuclear reduces average costs.

Edit: I see now. The original data is at least over 5 years old, at which point it’s possible that wind/solar may still have been more expensive than nuclear.

Editx2: The original book on which the original site is based was published in 2008/2009.

It’s not clear how much of the data on this new site has been updated.

See also, peak uranium : https://en.m.wikipedia.org/wiki/Peak_uranium

2017 known supply is enough for 130 years at current usage (supplying about 10% of global energy). Each doubling of production halves the peak timeline. Basically no one expects discovery to outpace usage.

So, at best, nuclear is a stop gap and part of a different long term solution. Which could be fine! But the extremely low LCOE and fast build time for modern renewables suggests that nuclear is simply losing the race for relevance.

Fuel is very small part in cost of nuclear generation; As fuel price start increasing, more sources become viable, including sea water. There is practically unlimited supply once it happens, and this is before accounting for reprocessing. (and reprocessing happens in France, for example)

Right, but the fuel cost goes up over time as extraction gets harder (eventually requiring entire new types of facilities, which themselves take a decade to build), even as wind and solar continue their exponentially decreasing LCOE cost curve.

The exponentially decreasing cost curve is the part that I think people haven't actually internalized. The arguments on the pro-nuclear side are pretty much the same as they were ten years ago. (right down to 'we'll have thorium in ten years!') But things are very different now: It's like arguing for large scale investment in punch-card sorting machines circe 1960. Yes, the punch-card sorting machines can be used to manage all your bank data, but the digital processing are getting exponentially better with time and have been actually better for a couple years. But the proponents of punch card sorting machines haven't internalized the message yet.

> even as wind and solar continue their exponentially decreasing LCOE cost curve.

What you think is an exponential curve is actually the left side of a sigmoid.

Your meme pertains to exponential /growth/, not exponential /decline/. Exponential growth in a population hits a limit as a population saturates, causing the sigmoid shape. Exponential decline hits a constant asymptote and bottoms out. For populations, that asymptote tends to be zero. For cost curves, as in the solar panel case, it will be something more like capital cost of production divided by panel lifetime, which can be a very small number indeed.

> Right, but the fuel cost goes up over time as extraction gets harder

Uranium demand is declining, there has been almost no Uranium prosection in the last decades; Therefore it's no wonder reserves are diminishing. If demand picks up, prospecting will renew, and a lot more uranium will be discovered. This is not accounting for thorium reserves, which have never been seriously prospected.

Current reactors (light and heavy water reactors) all use solid fuel, which is very inefficient due to use of once-through fuel cycle.

Because xenon is the most common fission product, and it's a gas, the reaction must be stopped before all fuel is used, as otherwise the solid fuel pellets would crack. If you assume 3% enriched uranium (U-235) and 97% depleted uranium (U-238) (a typical fuel load), the fuel pellets are unusable after about 1/3 of enriched uranium is spent. So the fuel is removed and "thrown away" while it still has 2% U-235 in it.

Switching to liquid fuel reactors assuming no other changes would immediately increase supply 3 times (because xenon simply bubbles out). Switching to liquid fuel breeder reactors ~ 100 times. Switching to breeders based on thorium - around 1000 to 10000 times.

Peak uranium is only a problem because we're using a very inefficient nuclear reactor technology - water reactors. Why? Because they were chosen by the military and the technology/know-how was already there. Efficiency was really low on the military's list of priorities.

Switching to solid fuel uranium breeders + fluid fuel thorium breeders gets you to around 4 billion years.

I thought fuel pellet cracking was already a tolerated thing. Pressure builds up in fuel rods due to escaped xenon and krypton.

There's more to it than that. The long-term plan for nuclear fission always has been and remains to use breeder reactors after we have ~1000 GW-scale non-breeder reactors in place. Because they can utilize the majority isotope of uranium (U-238) and Thorium rather than just the small natural amount of fissile U-235, breeders enable us to make 100% of the world's primary energy for about 4 billion years (e.g. roughly until the sun burns out) [1].

[1] https://whatisnuclear.com/blog/2020-10-28-nuclear-energy-is-...

The same point was made in the Hot Air book as well [2]

[2] https://www.withouthotair.com/c24/page_162.shtml

Since this is roughly the remaining lifetime of the Sun, there's a very strong argument to consider nuclear fission breeder reactors just as renewable as the solar-derived energies (wind, solar, hydro, biofuel)

Which means that nuclear proponents should use the cost of breeder reactors with reprocessing, not burner reactors with a once-through fuel cycle, when calculating the cost of nuclear energy. This will likely increase the cost of energy from nuclear.

I don't really know about that. After we have 1000 GW scale lwrs the prices of reprocessing might be different than today's prices.

And when we scale out wind and solar they will be cheaper too. Given the historical experience curves, this argument will favor those, not nuclear.

If we forced them to be honest we'd also force them to account for the huge carbon sink the plant represents until it has generated enough power to offset its construction footprint.

We need solutions that pay back as fast as possible, not stuff that will go neutral in 20 years.

> (supplying about 10% of global energy).

Current nuclear supplies 10% of global ELECTRICAL energy, not total energy. If you scale burner reactors to supply the 18 TW of primary energy demand the world uses, projected cheap uranium runs out rather quickly.

> (3.) carbon capture, and one gets to 75% emissions reduction with less than one percent of cost increase

Carbon capture and less than one percent cost increase looks suspect to me

Agreed. I didn't use it at first because I thought it would be cheaper to just reduce emissions than undo emissions, at least up until this 80% goal that the site poses.

Without any carbon capture, you're still at 61% emissions reduction and the cost actually decreases by 0.8% from today rather than increasing by 0.6%. If you get to 61% with the only change being "build nuclear and make use of it" (no lifestyle changes, no cost changes, no landuse changes), that would be amazing.

Hence my main question is about the nuclear aspect. The argument against nuclear is usually that it's super scary and dangerous (easy enough to disprove that with numbers, so long as you're not talking to someone from germany) and the fallback argument is that it's so expensive now that PV+wind became so much cheaper. This calculator seems to show the opposite of that latter argument (when looking purely at price).

Surely there are studies of LCOE for both when trying to produce baseload capacity. Personally, I suspect nuclear construction costs are dominant, but that should also be addressible through improvements in technology and policy.

Not a big surprise given the insanely high power density of nuclear reactors.

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