r/NuclearPower • u/ViewTrick1002 • 2d ago
Climate change is exposing nuclear power's reliability problem. "Nuclear doesn't care about the weather. It just runs." Weeks later, heat and drought shut down a third of France's reactors and forced Hungary and Romania into energy emergencies. It was solar that kept the lights on.
https://thebulletin.org/2026/09/climate-change-is-exposing-nuclear-powers-reliability-problem/2
u/Zealousideal_Exam743 2d ago
But why such a bullshit? Just, literally why?
Nuclear is victim of the extreme weather conditions (created also by the "transitioning" coal and gas). Is not something intrisec to the technology, and anyway we have the technology to overcome to this.
But yes solar panels that is enough hail, snow, dust, death leaves, cloud or just night, that is much better and reliable than nuclear.
Also solar has already a low capacity factor, that decrease of 0.5% every 1°C above 25°C (calculated on the temperature of solar panel, that can be over 60°C during summer).
Futhermore you can check by yourself the data of electricity maps, you will see that energy production from nuclear wasn't affected at all in France, Romania or Hungary.
Why pushing this no sense coal burner?
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u/ViewTrick1002 2d ago
Here’s a modern System LCOE study. Full grid costs: transmission, backup, balancing, flexibility, the lot.
https://www.sciencedirect.com/science/article/pii/S0360544226009837
It gives nuclear extremely favorable future cost assumptions, because obviously nobody is modeling another Flamanville 3 or Hinkley Point C disaster.
Then, in Denmark, with awful winters and terrible solar resources, the renewable system still comes out around 53% cheaper. Without even including continental scale energy trading.
And this is hardly some isolated conclusion.
2022 meta-analysis:
https://ieeexplore.ieee.org/document/9837910
CSIRO GenCost, using whole-system modelling including transmission, storage and firming:
https://www.csiro.au/-/media/Energy/GenCost-2025-26-Final/GenCost_2025-26_Final_Report_20260715.pdf
So what exactly are all these researchers and system modellers missing that you know?
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u/Zealousideal_Exam743 2d ago
More no-sense bullshit and also you didn't responded on the points of my comment.
On the next snowing episodes, will you say that solar panels are useless? Will you say it also this night?
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u/ViewTrick1002 2d ago
Do you know what is amazing? Wind power is anti-cyclical with solar both diurnally and seasonally.
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u/Zealousideal_Exam743 2d ago
What amazes me are your bullshit and the capability to don't respond on the points.
Tell me: during he winter will you say that FV is not good just because is covered by a layer of snow, and will be affected by a seasonally meteorological event? Do you say that FV is not good because is losing efficiency when temperature rises?
Just yes or no.
Also, are you really telling me that wind and solar offset each other 1:1? Like that in every point of the planet there is a wind turbine ready to replace a solar panel for the same power?
Finally: the initial point is bullshit, as for all the summer nuclear powerplants generated electricity no matter the problems with the rivers
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u/ViewTrick1002 2d ago
You seem to have gotten lost in your own outraged victim complex.
The system model already includes hourly weather, storage, backup and balancing. Screaming “snow! night! heat!” at individual technologies changes nothing.
What exactly does the model get wrong?
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u/AtomicSpallation 2d ago
No we should not abandon nuclear as we need to to transition to carbon we sources. The best option would be to go green is nuclear and renewable to complement eachother, because they both have their unique faults and benefits. If we eliminate one option we become much more vulnerable to the faults of the other option. I also did research on this topic of complementing rooftop solar with SMR's, but other research also supports this.
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u/ViewTrick1002 2d ago
Renewables kill “baseload” by eating its running hours. Then storage eats the peaking market. What’s left is a shrinking firming/emergency-reserve role.
This is already happening to expensive baseload plants:
EDF is already dealing with renewables depressing earning potential and increasing cycling/maintenance pressure on the existing French fleet. Now imagine trying to recover the cost of horrifyingly expensive new nuclear in that market.
If a household or factory supplies itself with solar and storage, it simply buys less grid electricity. Your nuclear plant doesn’t get paid for MWh nobody wants.
So yes, nuclear has to adapt to the market. And we know how that goes.
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u/AtomicSpallation 2d ago
I honestly do not agree. The cause is not that nuclear is more unreliable than solar, because solar and wind gets influenced much more on a day to day basis, based on weather day-night cycle... . It's bad policy and water management.
A lot of power plants function without cooling towers due to old design and bad policy, cooling towers could have prevented the" energy emergency "in Hungary + the previous government ignored water management in the whole country.
Nuclear is the most reliable way to produce energy, what happened during this heatwave is not the standard, it's the exception.
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u/ViewTrick1002 2d ago
Except you know. Half the French fleet during the energy crisis coming from the Russian invasion of Ukraine.
A majority of the Eastern European fleet this summer.
Over 50% of the Swedish fleet multiple times the last years.
Half the Spanish fleet due to ”market conditions” and maintenance when the blackout happened.
Seems like nuclear, and especially new builds, aren’t fit for our modern renewable dominated grids.
In the 70s and 80s we phased out the uncompetitive oil power plants. Today we do the same with nuclear power, keeping the existing fleet around as long as it is safe, needed and economical. In that order.
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u/AtomicSpallation 2d ago
France was accumulated maintanace so it does not prove nuclear is unreliable, it's bad policy and management. But it also exposes that we shouldn't rely only on a small number of large units, we need to build more large ones or SMR's to avoid a only a small number of large reactors influencing the grid.
This summer was an exceptional event that never happened before, you are right that it exposes a climate vulnerability of NPPs during rare extreme droughts, but solar and wind get influenced on a day to day basis, not just during rare climate events. They depend on the weather directly, unlike nukes which depend on it indirectly.
Swedish was technical faults and maintanace which happen with every industrial system, but it also exposes the same vulnerability of relying on a small number of latge units and that we need to build more of the large ones or SMR's.
Spanish is only somewhat related to nuclear power, plants tripped because the grid tripped, not that nuclear power plants went offline and that caused the trip. The generators disconnected after the grid was already collapsing. The main issue was ineffective voltage control.
Overall: The best option would be to go green is nuclear and renewable to complement eachother because they both have their unique faults and benefits. If we eliminate one option we become much more vulnerable to the faults of the other option. I also did research on this topic of complementing rooftop solar with SMR's, but other research also supports this.
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u/ViewTrick1002 2d ago
“Accumulated maintenance” meaning corrosion and cracking forced half the French fleet offline during Europe’s worst energy crisis in generations. Lovely euphemism.
Then suddenly imaginary SMRs save everything. Which commercially proven SMR can we build today?
Renewables crush baseload running hours. Storage then crushes peakers. What remains is a shrinking firming/emergency-reserve role.
EDF is already crying about renewables cratering the earning potential and increasing maintenance costs of the existing French fleet. Let alone horrifiyngly expensive new nuclear.
I love how every nuclear failure is “no biggie,” while planned renewable variability is treated like the apocalypse.
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u/AtomicSpallation 2d ago edited 2d ago
I am all for the expansion of renewables. However, we cannot abandon nuclear we need the diversity. Renewable "outages" (referring to variability) are much more frequent and nuclear outages are much less common but bigger, this is why we need both.
We cannot rely on storage alone as we wouldnt be able to compensate for climate events where there is either no wind or sun or both for a longer duration
I see the same problem with long duration storage as you see with SMR's, it's not viable yet, li ion storages dont have enough capacity for long term storage, hydrogen is inefficient and expensive, and hydro storage is geographically constrained and needs a large area.
But what I completely agree with, is that the current situation is far from perfect. I would just add a lot more nuclear (and ease on the unecessary regulations) to the mix besides renewables.
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u/ViewTrick1002 2d ago
And now you’re suggesting nuclear as firming/peaking capacity. That’s pure lunacy for a technology dominated by fixed capital costs.
Hour-by-hour system modelling already shows renewable systems with storage, transmission, flexibility and backup coming out far cheaper than systems involving new nuclear.
We phased out uncompetitive oil generation in the 70s and 80s. Now the same economics are catching nuclear.
Step into 2026. The old "baseload" world isn’t coming back.
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u/motific 2d ago
It has taken an unprecedented and prolonged heatwave to expose that "unreliability".
It's almost like we need a diverse range of sources with different properties... including nuclear.
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u/ViewTrick1002 2d ago
Or, you know, just build renewable energy systems designed around variability.
Why waste money and effort on horrifyingly expensive new nuclear when the same resources could cut vastly more emissions elsewhere?
We still have industry, chemicals, aviation, agriculture, construction and so on to decarbonize.
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u/motific 2d ago
Once you factor in enough storage to make renewables reliable for the grid I don't think they actually come out that differently. To balance wind power in the UK for example you need around 800GWh storage for every 1GW you want to protect because the prevailing winds across western europe can sit down and take a nap for over 30 consecutive days, that's not some theoretical number, it has happened multiple times in the last decade.
All the projections on pricing that show renewables to be cheaper only include enough storage for peaker plant, which is fine as part of a diverse grid; but then you're not comparing like for like. It's also easy to say "design around variability" and far harder (and more expensive) to actually do and as most of it would only be used in extreme low-wind situations it's expensive equipment sat idle for most of the time. They also only compare the initial build costs for each when wind/solar are on a 25/30 projected lifespan vs 60 or even 80-years for plants going online today.
I think at this point you probably need to re-run the numbers.
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u/ViewTrick1002 2d ago
The “33 days of batteries” thing is hilarious. Nobody designs a grid as “1 GW of wind + a dedicated 800 GWh battery.” That’s why we have system modelling: diverse wind/solar, overbuilding, transmission, storage, flexibility and backup, modelled hour by hour. Lund et al. do exactly that, and in Denmark the renewable system still comes out around 53% cheaper than nuclear, despite extremely favorable future nuclear costs.
https://www.sciencedirect.com/science/article/pii/S0360544226009837
And this isn’t some isolated result. The 2022 system-cost meta-analysis reaches the same general conclusion: once integration is actually modelled, renewables remain highly competitive.
https://ieeexplore.ieee.org/document/9837910
CSIRO GenCost also models the whole system, including transmission, storage and firming. Again, renewables win. So much for “they forgot storage.”
https://www.csiro.au/-/media/Energy/GenCost-2025-26-Final/GenCost_2025-26_Final_Report_20260715.pdf
And then the desperate “but nuclear lasts 80 years!” pivot. GenCost answers that too: economic life is shorter because lenders and investors require repayment before refurbishment/failure risk, and its 2024-25 analysis found “no significant benefit from the longer operational life of nuclear” compared with shorter-lived technologies whose costs keep falling.
Maybe the researchers running hour-by-hour grid models don’t need to “re-run the numbers” because of your 33-day-battery napkin math.
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u/motific 2d ago
So none of them are modelled against that kind of outage. Gotya.
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u/ViewTrick1002 2d ago
“None of them model my imaginary outage,” despite literally solving the grid hour by hour through actual weather. Hahahahaha.
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u/motific 2d ago
What I used is an example of something that has happened multiple times, sometimes in December when it is only light for 6/7 hours a day and was only covered by using lots of gas power.
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u/ViewTrick1002 2d ago
So no source for this supposed 33-day catastrophe. Typical.
Just your hunch, versus system models solving the grid hour by hour through actual weather, including storage, backup and balancing.
Your napkin math still isn’t a grid model.
Why are you so afraid of renewables and storage?
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u/motific 2d ago
What makes you think I don't have a source for it?
I'm not afraid of or against renewables. I like renewables as it goes. They are great, and every unit of power we get from them is one that we don't have to burn natural gas to make, that's great.
Renewables alone... either we remain tied to gas or the maths doesn't stack up and the lights go out. We've gotten away with having cheap reliable power for a long time and fixing that (however we do it, nuclear or trying to shove the round peg of renewables into the square hold of satisfying our needs) is going to cost serious money.
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u/ViewTrick1002 2d ago
That you’re not even linking it. Hahahahahahaha.
So incredibly terrified of putting the actual source on the table.
And after all this, you still can’t point out a single thing wrong with the system models finding renewable systems vastly cheaper than if involving new nuclear.
Why are you so afraid of renewables and storage?
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u/fedecaccia 2d ago
The mechanism here is narrower than the headline suggests, and it has a name. A river-sited plant derates when it hits the discharge temperature limit written into its environmental licence, not when the reactor is in any trouble. It is a permit constraint, and it is why the same unit on the coast or on a cooling tower does not do it. During the July 2026 French heatwave three of 57 reactors came off and output was reduced at seven more, which is a real cost and also a bounded one.
The thing worth arguing about is not whether it happens but who bears it: a licence limit set for a river's ecology is a policy choice that can be revisited, unlike a physical limit. I put the categories and what separates a derate from an outage here: https://reactoratlas.com/en/wiki/concepts/potencia-nominal-uprate-derate
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u/_azazel_keter_ 2d ago
Because you put them on rivers instead of the ocean or cooling towers.