There are any number of methods of dealing with this. Using natural bodies of water is a lower cost (thus highly popular) method of sinking heat. Palo Verde has been operating 3 large reactors in the Sonoran Desert in Arizona since the 1970s. There is no reason in engineering or physics that a power reactor must be highly sensitive to any particular lake, river or ocean's temperature. This is strictly about money, being cheaper to rely on a big "free" heatsink, and leaving too little margin for changing conditions.
This is entirely an ecological and safety concern.
The heat of vapourisation for water, converting liquid to steam, is 40.66 kJ/mol, or 2257 J/g. It takes a lot of energy to boil off water.[1]
That compares with the latent heat of liquid water, the energy required to heat one unit of water by one degree, which is 4.2 J/g*K (where K is the delta temperature in Kelvin).
Raising the temperature of input by, say, 10 degrees, would only reduce the cooling factor by less than 2%.
________________________________
Notes:
1. Which is why live steam is so dangerous. Steam condensing will release a huge amount of thermal energy, making steam burns especially harmful.
These heatwaves reduce the margin from both directions, a hotter intake means you have less margin on the outflow, and the lower flow rate means there’s less water to dilute that outflow. And apparently for that specific plant there’s also the water level not even reaching the intake.
Just imagine what it would spell for your car otherwise.
That is after all why they bring in water or air to car radiators, to cool them.
Probably only a single percent or so for a few degrees change though.
For your car, coolant temperature is typically in the 80-90C range. So the same change in external temperature would be a loss of ~10% of cooling efficiency. Still, cars have no issue running in 30C temps, and IME you have to go up to 45 to really need specialized cars.
So if you car can swallow 40C and >10% efficiency loss without a sweat, a NPP will have 0 issue using 30C water to cool their cores.
Or, if that's too much effort for them, use e.g. LiBr or other such atmospherically-stable salt that can maintain humdity equilibrium with dry ambient air.
The reason for even involving a water-based solution at all is because you can spray it or at least run it over dense corrugation (sheets alternating orientation, but overall with the channels roughly pointed upwards) "packed beds" with free contact between the coolant and the air, instead of having to maintain a barrier layer between the two (typical car/computer radiators, but also AC coils), which notably saves you from even a potential for a there-required barrier layer to leak and from having to clean such a barrier layer. If you make the corrugations large enough and have some simple mesh filters in the intake path that you just roughly shake/rinse/blow/brush off every once in a while, you can prevent particles larger than a rice grain from getting to the coolant in the first place and wash/rinse all the sand grain and smaller dust particles down into the coolant sump where their densities are far better matched (than air vs. dust) and volume flow is much easier to handle/filter.
The big part of these is still that they don't require active fan ventilation to cool radiators, which would be a substantial increase in critical electrical power needed after a SCRAM to keep the core from melting down; vs. the passive evaporative cooling towers and the KOH/LiBr non-humidifying variant I mentioned.
Even using industrial air-cooling design you'd need on the order of a million sqm or two (for reference a good quality computer heatsink is about a third of a square meter worth of fins)
https://en.wikipedia.org/wiki/THTR-300
But it was admittedly a huge cooling system for a reactor that only produced 750 megawatts of thermal energy.
The pressure of a condenser at 90F (hot summer day) is about 1/20th of an atmosphere and ... pretty obviously the pressure of a condenser at 212F is about one atmosphere. You can't just arbitrarily decide to change the low pressure side of a turbine like that, its not going to turn out well. You could, in theory, design an entire thermal plant coolant loop to deal with the condenser running at 1 atm instead of 1/20th atm but most will not.
There are also heat flow rate issues where the higher the delta V the higher the watts. Regardless of condenser pressure issue above, if a heat exchanger can pull 1 MW across a 150 degree delta-V then if you run the cold side much warmer at only 15 degrees delta V it can only "pull" 0.1 MW of heat. Its surface area doesn't magically get bigger LOL. Remember that for every watt of electricity you get to dump around three watts of thermal heat. If you lose 9 MW of cooling power you lose 3 MW of output electrical power. You have to move more heat than non-engineers expect, to generate electricity.
Its a simplification, but for various reasons they like to design the hot side as hot as possible, so if you lose 100F of cooling you can't keep the same power output and simply run the hot side 100F hotter than normal and keep the same flow rate. Absolutely nothing good will come from overheating it like that.
You could engineer a thermal plant (thermal as in coal, nuclear, burning recyclables and biowaste, anything to make steam) that runs at an ideal hot side of 212F and let the hot side literally boil water in a pool. However, they don't make plants like that IRL and trying to force it under those conditions would turn out very bad... The first thing that comes to mind is gunk buildup and higher corrosion rates. Steel (generically speaking) corrodes in water about twice as fast per every 20C increase, so turning a cold water plant into a water boiler would to first approximation cause about a year's worth extra corrosion per month. Could be designed around, but I would not want to cowboy a nuke and just try it. Some of those parts are very expensive; even if you can safely run the plant and replace the corroded parts at a substantially accelerated rate, the cost of power due to corroding the cold side parts might make the power too expensive even if its "safe enough", making it cheaper to just shut down. Moving large amounts of water (or air) is extremely expensive, both capex and opex, so an additional 10x higher once in awhile here and there could be a lot of money...
Any new build can and will include cooling adapted to hotter conditions.
Batteries (or pumped storage hydro, which is more like a gravity-driven capacitor)
But yeah batteries would be nice.
It's a meaningful contribution I would have thought.
[0] https://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power...
Starting this year, in Romania you cannot put new PV capacity online without the storage for it, is mandatory. Possibly for existing ones, but I am not sure.
They just absolutely cannot math the math which leaves ideology and this ain't France.
It's very obviously not in the interests of "big fossile" to go either solar or nuclear.
No, I'm not. Not in the slightest.
Number in top right go up. Monkey brain feel goooooood when that happen. Monkey brain keep doing behavior that make that happen.
> It is much more likely that they simply aren't very thoughtful.
They're plenty thoughtful. They'll contrive all sorts of arcane logic, plausibly deniable lies and witty turns of phrase (some of which are quite impressive).
What they're not is self aware (the dishonesty is a byproduct of that).
> Complex webs of deception
Those are possible but I don't think that's what's happening here.
> but it generally relies on some group having a clear financial incentive to misdirect.
Internet fanboys work for free. They have no financial incentive. Therefore we fall back to the monkey brain incentive.
However, hopefully, they change the plans for (stalled project) Paks 2, because that would've used the same cooling system as the first one.
If for the sake or discussion we simplify cooling to four options:
1: just passing river water through a heat exchanger for cooling
2: ingesting river water, using it for cooling, then passing it through a cooling tower before returning it to the river
3: pass the water output from the cooling tower directly back in the cooling loop, only ingest enough water to replace evaporation
4: fully closed loop via direct heat exchange with air
Then 4 is not very viable. But a lot of nuclear plants are stuck at 1 or 2, and each step up the ladder would allow them to operate in worse conditions. This one seems to be at version one
Heat engines do turn heat into mechanical energy (motion).
What they don't do is do this with infinite efficiency.
In practice, Carnot engines (heat engines) tend to operate at efficiencies between about 20 to 50%, with an average close to 30% percent. This means that most thermal electrical generation produces roughly three times as much heat as it does electricity. This applies across thermal mechanisms: diesel generators, gas turbines, coal-fired steam, and nuclear-powered steam plants.
There's some room for increased efficiencies, and multi-pass systems, or systems with incorporated thermal applications (district space heat, industrial heat, food preparation) can achieve higher net efficiencies, though I believe the peak is around 60%, and that is rarely achieved.
The other parts of the generating cycle are far more efficient. Generators typically operate well above 90% efficiency (mechanical energy in to electrical energy out), and distribution typically sees about 6% losses.
But that first thermal step costs a lot. There's no such thing as a free lunch.
This is true whether you use an engine, a river, or a solid-state fully electronic device. Even humans must obey this law, and indeed there has to be some air movement for us to cool down using our sweat, and interrupting or changing that air movement costs energy and therefore increases entropy somewhere.
Heat engines are most efficient when the temperature difference between the hot and cold side is high, so you need to keep it that way to extract energy.
A nuclear power plant achieves this by converting extreme heat from a small, but very angry rock to a huge lake of slightly warmer water.
There exist reactor designs which operate at higher temperatures, thus increasing efficiency, but they're complicated as everything needs to be more heat-resistant.
True there is a small different in NPSH pump limit of hot summer water vs cold winter water, but not as much as you'd think.
Its not that the intake pipes are hanging out in the breeze above water; most pumps are designed not to cavitate at a certain input pressure (often pretty low) and I was bored enough to look it up and when the river is 134 cm below reference at this site, the pumps will be very unhappy long term if you keep sucking water in. They'll keep running, at a reduced rate, but cavitation will cause serious issues. At some sites, perhaps not this site, filtration systems (grates and stuff) on the input are designed for a certain ideal pressure and ideal flow rate, so that can also be a problem.
Thermal limits are also very arbitrary and designed to a financial limit. Most plants worldwide are limited to a delta V, I suppose there could exist an environmental law that limits to an arbitrary fixed temp. Normally if 10 gallons/sec heats up 10 degrees, then 100 gallons/sec would only heat 1 degree. But it would cost 10x as much and only be needed a couple days/year in the driest summers, so a tradeoff point, well chosen or not, was selected. Most absolute limits are utterly ridiculous like 90F. The only long term way to maintain a river at or above 90F is an air dew point of 90F and most people will be dead by then. I find it improbable the water temp is too high, everyone without air conditioning would already be dead if the dew point were substantially over 90F. You could probably "cook" a small lake or dam area with a nuclear plant into something like a giant hot tub, but not a free flowing river.
Looking at the mass media coverage, its mostly pictures and discussion of low water levels (the true cause) followed by journalist and consumer discussion about water temps, there is no meeting of the minds between the engineers and the general public and AI and journalists.
If for whatever weird reason, river levels were low in the winter, low NPSH at the pumps would shut it down just as effectively at a water temperature of 1 C. Large industrial water pumps react extremely poorly to low input pressure.
https://www.euronews.com/business/2026/07/13/france-shuts-do...
https://www.reuters.com/business/energy/hungarys-paks-nuclea...
We keep having folks here argue that nuclear, not renewables are the path to take to get rid of fossil fuels. I have strong doubts - it feels like that doesn't account for the sad realities of climate change.
There is simply NO safe level of fossil fuel use.
If someone is getting wiped from the mix because of renewables, it is coal and fuel, not nuclear.
About 85 percent of the total primary energy supply in Iceland is derived from domestically produced renewable energy sources. Use of abundant hydroelectric and geothermal power has made Iceland the world's largest electricity producer per capita.
What works for Iceland works in few other places to the same degree (New Zealand, Yellowstone, places with thin crust and feisty caldera's).
Iceland has geothermal, which is amazing, but won't help central Europe.
This is important because wind season anti-correlates with PV season.
Plus, it's not like north-south power lines are beyond the wit of mankind. The US western interconnection includes both Canada and Mexico: https://en.wikipedia.org/wiki/File:NERC-map-en.svg
Not for the combination of [continent-wide, offshore, the Atlantic coast].
The Atlantic continental shelf isn't correlated with the Baltic.
Offshore Dunkelflaute is much shorter than on-shore.
> Storage in the required dimensions is an unsolved problem.
Also false. The required quantities even of batteries is comparable to electrification of road transport.
Also, independently of batteries, hydro plants come in two flavours that people often mix up: generation, and storage. Of these, only generation requires an associated upstream supply and watershed; storage can be done with a hole in the ground, of which there are plenty, and just the currently and soon-to-be closed coal mines in the EU can be converted to around 13 TWh of pumped storage: https://gfzpublic.gfz.de/rest/items/item_5038282_1/component...
And it's not like we can't dig more holes if we wanted to, we dig holes to get out rocks even though rocks are one of the cheapest things you can buy.
How do you transmit the power? Do the countries on the Atlantic even want wind power, set up the transmission lines, and pay for it?
> Offshore Dunkelflaute is much shorter than on-shore.
That reduces the storage requirements a bit, but there is not nearly enough offshore. And offshore is expensive. That's why it's getting harder to find investors.
> The required quantities even of batteries is comparable to electrification of road transport.
That doesn't prove it's possible, but makes it even harder to get the required quantities.
> hydro plants come in two flavours that people often mix up: generation, and storage
Hydro requires the right geography. Is there any potential for hydro left in central Europe?
> EU can be converted to around 13 TWh of pumped storage
That would be a good amount of storage. But has this ever been tried? I would guess that's quite dangerous: https://www.youtube.com/watch?v=LseK5gp66u8
The usual way.
> Do the countries on the Atlantic even want wind power, set up the transmission lines, and pay for it?
They can sell the power, you know. This already happens.
> That reduces the storage requirements a bit, but there is not nearly enough offshore.
It more than covers it.
Even a Dunkelflaute period is reduced, not zero, output. Those seas are huge, and the normal wind there is fast; even on a continental-shelf-spanning Dunkelflaute (much rarer than "just Germany and Poland"), the capacity in those waters *even with that reduction* is more than EU demand just by itself, which in practice means "not building as much as possible".
> And offshore is expensive. That's why it's getting harder to find investors.
Compared to onshore wind. But even offshore wind is cheaper than new-build nuclear, coal, and has strong overlap with new CCGT.
Even then, it's not hard to find investors: the US went as far as banning it because the investors were actually happy to invest.
The limitation on investors right now is that we're transitioning faster than any previous energy transition before, while also having other things to also invest in. It's like how big tech in the US is running out of people to get money from to spend on data centres, the limit isn't actually building them, it's how fast they're getting built when your answer to "how many would you like to order?" is "yes".
> That doesn't prove it's possible, but makes it even harder to get the required quantities.
The fact that EVs are for sale, however, does.
> Hydro requires the right geography. Is there any potential for hydro left in central Europe?
I thought you might say something like that, *which is why I literally wrote what I wrote*:
people often mix up: generation, and storage. Of these, only generation requires an associated upstream supply and watershed; storage can be done with a hole in the ground, of which there are plenty
Also, I already saw all of Tom Scott's videos when they were new. As per the document:
Finally, the realisable potential includes projects that are not only technically and economically feasible but also aligned with regulatory, environmental, social and implementation timelines, facilitating their implementation within short to medium time frame.No, it's not. Decommissioned nuclear plant infrastructure used as massive battery storage.
https://gesi-deutschland.de/en/gesi-project-presented-in-gro...
The following table shows that in total 2264 installations have been identified in the EU ETS to be power plants, which have reported emissions in at least one year since 2005. The fuel of 1440 power plants have been identified. Of this there are 124 lignite power plants, 284 hard coal power plants and 2 power plants using blast furnace gas. There are 57 power plants using oil products. The majority of the plants uses natural gas (858 plants). About 824 plants have not been matched to a fuel yet.
I don't have a clue either. Don't ask for my vote on how to power a country. Take my taxes and use them to listen to experts
Why is it a good thing that everyone and their brother seeks to apply state violence to micromanage what should be a fairly arcane technical issue?
>We can't let decisions like these be taken by unelected technocrats alone.
Do you feel the same way about topics where your opinion differs substantially from the local majority?
Edit: I don’t understand how you get from „political decision“ to „state violence“. Politics are at play at all levels of civilization where actors have different goals, from your dinner table and your company Slack to democratic institutions.
I almost hesitate to ask, do you think that is the centralised or decentralised option?
And, more directly, that is a bad theory. The billionaires will make money either way. It doesn't make a lot of difference to them as a class. They'll have an inclination to the cheaper form of energy because more energy -> more economy -> more money for them.
The venn diagram between people who act like renewables are "freeing" (which make no mistake, they absolutely could be) and the people who advocate nonstop for government management of how they are deployed is too close to a circle for me to take such commentary seriously.
>One of these options makes it much easier for the billionaire class to continue extracting money out of the people.
Ah, yes, billionares. Famous for not getting a cut when I buy a plug in solar panel from my preferred e-commerce site or big box store. /s
The billionares have their money in everything. They get a cut of everything. You're just changing who gets the cut. And even if no billionaire is getting a cut, a publicly traded/owned investment bank or other corporate interest that would replace them is not really any less evil.
>: I don’t understand how you get from „political decision“ to „state violence“. Politics are at play at all levels of civilization where actors have different goals,
By not gaslighting myself into thinking politics is anything other than the process of deciding where, when and how state violence is applied.
What backs up all those decisions other than credible threat of violence?
Where did the person you are replying to even hint at that? I think this may be your own prejudice spilling out here.
> The billionares have their money in everything. They get a cut of everything. You're just changing who gets the cut.
Oh ok, I guess let's just accept this as is forever. Any attempt to try to improve this situation is futile and stupid (for example, as said, making it more difficult for them)
>What backs up all those decisions other than credible threat of violence?
I don't know, do you only act in fear of the threat of violence from the state? In democracies politicians are legitimized by their voters, what you are describing sounds more like an autocracy.
At some point it will be the new normal.
Every power source has their tradeoffs, and I don't think anyone is denying that.
What I do think is that people are making up arguments or statements that Other People have and call them out on it.
Restoring river water levels can't be done through technical solutions though, they rely on the weather and we can't control that. The European river levels are largely influenced by inland rain, snowfall, and glacier forming/melting; snowfall and rain has been meagre this year, glaciers have been melting and receding for decades now.
Then we could stop the nuclear plants when needed for cooling and maintenance
The problem is we don't have enough storage to use it after dark.
https://www.dert.hu/hu/sajtoszoba/0/141 (in Hungarian, couldn't find an English source)
https://en.wikipedia.org/wiki/Hunger_stone