this post was submitted on 26 Aug 2023
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Uranium is $128.30/kg

After enrichment, conversion and fabrication that's $3400/kg for 4.95% fuel.

At 36-45MWd/kg and a net thermal efficiency of 25% or $12.5/MWh up front.

With a 90 month lead time (72 month fuel cycle and 18 months inventory) at 3% this is $16.2/MWh

Which some solar projects are now matching

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[–] Uranium3006@kbin.social 15 points 1 year ago (3 children)

Are we talking just nameplate capacity or including the energy storage needs in the price? It's not really apples to apples unless you compare the costs of running each 24/7

[–] monobot@lemmy.ml 16 points 1 year ago (4 children)

And are we taking into account safe storage of nuclear waste for thousands of years (which we as civilization still don't even have) or not?

Today's journalists are really superficial.

[–] Touching_Grass@lemmy.world 12 points 1 year ago* (last edited 1 year ago) (1 children)

That's what blew me away. People keep saying a lot of hand wavy stuff about storage but when you really dig into there isn't a great solution other than keeping an eye on it for a few hundred years. Making private company's responsible for stuff that generates no profits and requires repeated Inspection's and maintenance doesn't sound good to me.

We absolutely need nuclear. But we should approach it cautiously. I don't think discussion about nuclear is as cautious as it should be. But that's par for the course with humanities track record

[–] schroedingershat@lemmy.world 6 points 1 year ago* (last edited 1 year ago) (1 children)

There's no need to consider nuclear. The power storage requirements for a 100% - epsilon renewable grid are vastly smaller than the amount of battery that will be deployed to EVs in the next few years.

https://www.nature.com/articles/s41467-021-26355-z

Those batteries can be used either after they degrade to the point where the EV needs a new one, or while still in the EV if a small fraction of owners participate in V2G.

Additionally the accessible uranium reserves cannot make a significant impact on the world's energy requirements.

In 8 million tonnes of accessible natural uranium there are about 56,000 tonnes of U235. Fissioning all of this yields around 5000EJ of thermal energy Exhausting all techniques of reprocessing and breeding that have actually ever worked, there's about 10,000EJ.

The world used 620EJ of primary energy last year so the absolute most generous interpretation is there are 16 years of accessible fission energy, In any realistic scenario it's much, much less.

The amount of energy that can be provided via fission with current technology isn't a meaningful contribution and can't be deployed in a meaningful timeframe.

There may be niches where GW scale LWRs are a much better choice than other options. On the off chance they do crop up, what little uranium 235 there is should be reserved for those.

[–] Suoko@feddit.it 1 points 1 year ago

It still sounds crazy to most people : it's a long way to go that should be paved for speeding up modern consciousness.

[–] chaogomu@kbin.social 7 points 1 year ago (11 children)

Fun fact, That "thousands of years" of storage is entirely a man made limitation.

95% of nuclear waste is unspent fuel. That's the source of the "thousands of years" waiting for the more energetic parts of the unspent fuel to decay.

There are a couple of nasty decay side products that last a long time in there, but those can also be fed into a reactor to be burned away. That's about 1% of waste. (mostly plutonium)

Pretty much everything else, the remaining ~4% or so of waste, is only really super dangerous for about 60-90 years, and only radioactive for about 300.

Another fun fact, a lot of that 4% is actually valuable in various industry, including nuclear medicine.

I always point to this video on the subject.

Sadly, Jimmy Carter signed a ban on refining waste, and then got it incorporated into some international agreements. He thought we would just bury the waste again, it came out of the Earth, it could go back in until we were ready to refine it and move on. Sadly, Nymbyism killed that plan.

[–] monobot@lemmy.ml 3 points 1 year ago (1 children)

Are we talking about present or future?

Nuclear has a chance in thorium and malten salt reactors, uranium is made for nuclear booms, not for safe energy generation.

Sadly, no one is investing enough in thorium and malten salt to make it available in next 10-20 years, we have better chance in fusion than thorium.

Until than, sorry, but while you are right, that technology is not yet available.

[–] chaogomu@kbin.social 1 points 1 year ago (2 children)

Okay, some basic physics here, to make thorium useful, you have to convert it to uranium (specifically uranium-234)

That's how a molten salt reactor functions, they use a seed of fissile material to breed the thorium into protactinium, which then decays into uranium.

Once you have the u-234, you can use it to breed the thorium, but you do need that seed of either u-235 or plutonium.

As for u-235 and u-238, well, those are full of harvestable energy as well. U-235 is what we burn in reactors because u-238 is fertile, not fissile. U-238 breeds up to p-239, which can explode if you know what you're doing, but can also be burned in a reactor for massive amounts of power.

We have the technology to do all of this right now. It's not 10-20 years out, it's today. What we don't have is an easy way to overcome decades of oil company anti-nuclear propaganda.

[–] Uranium3006@kbin.social 1 points 1 year ago (1 children)
[–] chaogomu@kbin.social 1 points 1 year ago (1 children)

So it is... That's what I get for typing that completely by memory.

U-234 is the side product... It's another fertile form of uranium that can form when you don't get the protactinium out fast enough...

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[–] schroedingershat@lemmy.world 1 points 1 year ago* (last edited 1 year ago) (1 children)

No breeder program has ever worked. The best was a couple of low burnup proofs of concept of breeding. They all failed trying to do proof of concept for the reprocessing step -- usually after many billions in subsidies.

Running a full fuel load of the steady-state isotope mix hasn't even been attempted.

[–] BastingChemina 1 points 1 year ago (2 children)

https://en.m.wikipedia.org/wiki/Superph%C3%A9nix

Super Phoenix was a prototype super breeder reactor built in France. It has issues in the first years (normal for a prototype) but by the end it was running with an availability of 96%.

[–] schroedingershat@lemmy.world 1 points 1 year ago

Also you're lying about the second part https://pris.iaea.org/PRIS/CountryStatistics/ReactorDetails.aspx?current=178

You see, the rule of thumb is very easy. If a nukebro or industry PR tells you something, there's a 96% chance it's a lie until someone else checked and they backpedalled at least 5 times. This is in spite of being forced to report the truth through other channels much of the time.

[–] schroedingershat@lemmy.world 1 points 1 year ago (1 children)

Like every other program, if it never made more fissile material than was loaded with, and then ran on that material, it's just a U235 reactor that caught fire more often

[–] BastingChemina 1 points 1 year ago* (last edited 1 year ago) (2 children)

Correct me if I'm wrong but I don't think superphenix used any U235. The fuel is Pu239 and U238.

So I don't understand your claim since no U235 was used in this reactor.

Edit: The reactor in talking about never caught fire. Your whole message is false information

[–] schroedingershat@lemmy.world 1 points 1 year ago* (last edited 1 year ago)

The Pu came from either a graphite pile or an LWR like all other Pu and wasn't involved in any process that made more than was inserted and turned into waste. MOX with extra steps and no closed cycle is still just MOX.

Also it shut down in 1992 because of air in the molten hot sodium. What do you call hot oxidising sodium?

So far we've got:

Combining oxygen with sodium isn't fire.

Running for a total of 6 months in ten years is 96% availability.

Net consumption of fissile material with no attempt at reprocessing into fuel for another cycle is breeding.

Net importing electricity from germany (and importing every month except for spring and autumn where local wind and solar is most abundant) is exporting "large amounts".

Do you even understand how ridiculous you sound? Like is this a self-humiliation thing?

[–] schroedingershat@lemmy.world 1 points 1 year ago* (last edited 1 year ago)

For anyone still reading, Phenix's fuel cycle (superphenix never really did anything at all except break down but it's basically the same, just a little bit higher burnup so slightly more Pu and energy at the last step).

  • Mine 3000t of uranium ore from Nigeria. Leave 2999t of very low level radioactive heavy-metal laden rock and sulfuric acid slurry behind in a poorly built dam for the people of Arlit to deal with.

  • Separate 130kg of ~4% enriched U with 5kg of U235. Leave 870kg of depleted but highly toxic and corrosive UF6 in a barrel for your grandkids to deal with.

  • Put the 130kg of fuel in a LWR. Get ~100TJ (140TJ in a gen iii reactor nowadays).

  • Separate the 1kg of Pu remaining, dump most of the Cs, Tc99 and a few other fission products into the north sea (which is still detectable in safe, but high levels in fish in Norway). This bit costs more than mining the fuel did. Radiate your own people a little with Xe-85.

  • "Save" the 123kg of Uranium with 1.2kg of fissile isotopes in a "strategic reserve". Nobody with a centrifuge anywhere outside of Mayak will ever enrich this because it is highly contaminated with U234, U236 and U232. It's waste. You could pretend it had 20TJ in it if you were a nukebro.

  • Put the 1kg of Pu in Phenix. Fission 20g of it. Get 200GJ.

  • Now you have 20g of super-weapons grade plutonium and 980g of plutonium that is too full of Pu240, Pu241, Pu242, Am and a few other elements to use. It's waste, nobody will ever enrich it.

Congratulations! You did a closed-loop fuel cycle! Energy solved! You have 200GJ worth of fissile material and 0.1% more energy than just using an LWR! If you did it again you could get 0.101% extra energy!

Now let's go spend the same amount as $85/W PV for the same energy output costs in 1976 on superphenix!

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[–] schroedingershat@lemmy.world 3 points 1 year ago* (last edited 1 year ago)

This is just the marginal cost of the front end of the cycle ignoring the back end and all other fixed or marginal costs.

Ie. If you already have bought an SMR in a high-solar-resource region, is it cheaper to buy fuel to run it during the day or to buy solar panels instead and turn it off. The answer being it's a wash right now, but uranium is going up for the moment and solar is going down for now.

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[–] MrMakabar 7 points 1 year ago

It is comparing the cost of nuclear fuel to generate a kWh of electricity vs the cost of a solar to generate a kWh of electricity in what is a great location.

So it excludes the entire construction cost of the nuclear plant as well as operating the nuclear plant. It also excludes any sort of storage costs for running the grid with solar. However we are talking about the UAE for solar, so cloudy days without sunshine are basicly not a thing. So you really only need a nights worth of batterie storage. Most consumption happens during the day, so we are talking maybe a third of total generation would need to be stored. So for a MWh of daily use and $333/kWh. Given that you need 333.3kWh of storage, which costs $111,000 total.

Since this is only fuel costs thou and the nuclear plant has to be built as well, which is not included in fuel costs. So lets look at what 1MWh a day would cost in terms of nuclear power plant. Olkiluoto3 was just finished for $12billion for 1,600MW or $312,500 for a MWh per day.

So in this case you are basicly betting that a nuclear power plant lasts three times longer then the battery storage and battery storage costs are not falling, which is propably not going to be the case. Also a bunch of technologies do not care too much about when they get power. If you for example have super cheap electrolysis to produce hydrogen during the day, that is an intressting use case. Also grids propably have more then just one power source, so stuff like wind power, hydro and so forth might also be options in some grids and solar prices are falling over time.

[–] schroedingershat@lemmy.world 2 points 1 year ago* (last edited 1 year ago)

This particular pearl clutch is even stupider than usual when it was already explicitly not apples to apples. For a time-dependent load you have the other 90% of the budget for the nuclear reactor to figure out storage (or to meet daytime loads or flexible loads).

This comparison is fuelling an SMR you already have vs. turning it off but continuing to staff it and pay for the back end of the fuel cycle as if it were running when it's sunny and running solar instead.

If the marginal cost of the SMR is higher than the all-in cost of solar, then it is always optimal to build the PV array (so long as the grid is not saturated with solar) even if you already have surplus nuclear. So the much bigger portion of the SMR cost (the reactor and fixed O&M) has to justify itself just on the loads that solar cannot feed.

Of course this is not true everywhere yet (and this does not apply to more efficient large reactors), but the niche for SMRs is smaller than traditional reactors and shrinking.

[–] BestBouclettes@jlai.lu 14 points 1 year ago (48 children)

Why is it always comparing solar vs nuclear. What we need to compare them against is fossil fuels. Nuclear and renewables should be used together if we want to phase out fossil fuel in a timely manner.

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[–] Mojojojo1993@lemmy.world 7 points 1 year ago
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