Here in Switzerland during some heatwaves they have to shut down nuclear plants too because the river water is too warm and adding warm water to it would kill the fish.
The reactor absolutely is not going to care, it’s the tertiary cooling circuit cooling for the steam turbines, it will have cooked off everything downstream long before it’s an issue.
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.
Backing this up, these high numbers are for typical cooling towers where they vent to atmosphere.
Once you get into closed loop PWRs the numbers get crazy. Actual figures for Naval Nuclear plants are classified, but as a nice round number example if you pressurize the secondary loop to 250psi you end up with about 1,725 kJ/kilogram to boil it.
No that's never the problem, even 40°C intake is cool enough to cool a reactor, it's all just a question of returned water temperature that can be harmful to a river if too high (generally the limit in Europe is set to 30°C).
It can vary by the river too (e.g. I remember Switzerland pulling back a reactor around 25 intake), and iirc there’s an absolute limit on the outflow (you don’t want to boil alive the stuff just off of the plant) and a relative one a bit downstream (you can’t heat the river to 20 when it’s freezing).
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.
Convection cooling efficiency is mostly dictated by the delta in temperature between the hot and cold source. Coolant temperature in the core is in the 300C ballpark. So the river going from 20 to 30C is roughly a 0.3% change in cooling efficiency.
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.
The temperatures aren't high enough to do that (or air cooling) efficiently enough. Some experimental designs for high temperature operation would have that as a possibility (e.g. molten salt reactor designs). I think a Chinese research project is looking into air cooling for nuclear power in dry regions.
There's also the potential of co-locating non-evaporative cooling with CO2-scrubbing using a strong KOH solution in the big cooling towers and regenerating the hydroxide with calcium hydroxide (regular process done in kraft process paper mills, though they use NaOH with slightly favoured properties over KOH).
KOH is very hygroscopic; it does not have to be humid for a barely-still-liquid solution to actually dehumidify in the process.
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.
Not really, a large reactor is way too power dense. An EPR reactor has a thermal output of 4.6GW. And the tertiary is cooling steam turbines so it's below boiling, you'd need something like 10 sqkm worth of surface, per reactor, with an environment cool enough that this could actually radiate.
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)
Mochovce nuclear power plant, with evaporative cooling towers, uses around 21.6 to 24.8 million m³ per year depending on operating units and seasonal weather demands. (About 0.7 m³ per second)
OP is correct, the people making fun of OP don't have an engineering background.
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...
Would a cooling pond with controlled discharge into the river maybe mitigate this problem? One could also cycle the water from the cooling pond through the plant's cooling loop. The worse that could happen is evaporate the water from the cooling pond which is gets replaced with new water (sans fish) from the river.
> Would a cooling pond with controlled discharge...
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.
Nuclear plants can run with those hyperboloid cooling towers as the sink for waste heat. They are just a lot more expensive to build, run and maintain compared to using river water.
There's plenty of work happening with adapting non evaporative cooling loops for data centers. Maybe that can be applied here too, even if to mitigate some of the cooling needed?
2:1 implies 33% thermal efficiency to the grid which is commonly achieved in normal operations.
Unfortunately engineering means you can’t work with such overly simplified models. Many ways of dumping heat run into issues from solar gain prevents dumping significant heat under the employe parking lot etc.
I don't disagree but am having a hard time parsing the second half of your comment.
In my experience we saw some losses when taken as a system that prevented us from hitting 2:1, but they weren't anywhere near 50%. We also ran closer to 40% than 33% thermal efficiency in the power generating loop, so many of the system thermal costs are baked into that 33% efficiency to the grid.
Basically, each reactor install will have it's own minor issues. Overall they should be hitting around 2:1 as an entire system. If they aren't there is something going on that I haven't come into contact with (which is quite a lot, I'm sure).
> hard time parsing the second half of your comment.
I’ll put it as a spherical cow engineering problem. Let’s suppose the temperature is 30C and you want to dissipate 2GW of heat across a 1kmx1km flat plate, what temperature will it get? That’s a relatively straightforward calculation if you don’t need high precision.
However in the real world it wouldn’t have a single equilibrium temperature. 30C at night the heatsink would be one temperature and in the daytime it would be a different temperature due to sunlight.
Evaporative cooling largely sidesteps this issue, but it’s worth keeping in mind why that’s chosen over other seemingly cheaper options.
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.
People arguing for one alternative over the other are usually politically motivated. I feel like you are doing the same. Sometimes nuclear is a good fit, sometimes renewables is a good fit, sometimes fossil fuels are a good fit. Most of the time a mix is the best fit. It depends on what you are optimizing for and what is geographically, (geo)politically and economically possible. All these systems are then built using assumptions, sometimes those assumptions no longer make sense after a certain period of time and sometimes you just temporarily or permanently have to adapt to the changes in the environment. This is an unusual but expected scenario for the nuclear plants along the Danube.
I'm not really opposed to nuclear power politically. I just think it's a non-starter given the much higher cost, complexity of buildout and lack of reliability.
Storage of energy in the dimensions required for weeks with almost no wind is an unsolved problem. Right now, we can't store enough to make it through a single night without using fossil fuels. Most countries don't even have the capacity to store the energy for a single hour.
As we can store fossil fuels for weeks of demand, we can store the required energy in chemical form, no? Germany has huge natural gas storage, for ezample.
Geothermal and storage is worth investing in, investing in nuclear is not. NPPs are simply too expensive and you won't find investors unless you heavily subsidize it with tax money. Only compnies willing to invest in NPPs are those with virtually free money: the handful of AI big tech giants.
We're building the factories to make them as fast as we can find investors with money to spend on them, because they're already cheaper than fossil fuels which are themselves cheaper than nuclear.
Iceland is a small area, small population outlier literally sitting on two plates rubbing up against each other and a relative excess of active volcanism and large lava fields.
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.
Countries like UK, Ireland, Germany, Danmark, Netherland, Poland also have dark winters. Solar in winter is only about a fifth of production in summer months.
Iceland has geothermal, which is amazing, but won't help central Europe.
Those places also have a huge wind resource in the form of the North Sea, for Ireland whatever the other bits of that submerged continental shelf are called, and for Poland the Baltic: https://globalwindatlas.info/en/
This is important because wind season anti-correlates with PV season.
Yet there are whole weeks practically without wind in winter. And most climate models estimate that global warming reduces wind further. Storage in the required dimensions is an unsolved problem.
> Yet there are whole weeks practically without wind in winter. And most climate models estimate that global warming reduces wind further.
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.
> The Atlantic continental shelf isn't correlated with the Baltic.
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
Max comment nesting reached. Instead of going through your response one by one, let me just say one thing: the premise and promise of the whole energy transition are based on studies that completely underestimated the physical and engineering challenges in practice. That's why we are where we are. Energy costs have gone up; CO2 emissions have not. I wouldn't believe any study before it has been implemented at scale, at least in a region or small country.
> 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
And then linked you to a document, with a quote from that document, about using coal mines. The document you replied to with doubts, supports the conclusion you've just denied.
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.
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.
Agreed, whenever I hear someone say "we need more/less nuclear and less/more solar/wind", I hear "let's burn more fossil fuels while we uselessly split hairs".
Unless the scenario is totally different where you live, pro-nuclears are mainly "we need more nuclear, less rerewables, don't care about fossils, just guaranteed production", while pro-renewables are mainly "we need more renewables, less or no fossils and as few nuclear as possible".
If someone is getting wiped from the mix because of renewables, it is coal and fuel, not nuclear.
The point they are making is that climate change will further push these conditions, so are we willing to build more nuclear power plants, knowing that by the time they are ready to go online this problem will be worse? Or better to invest in renewables which can be implemented today and will alleviate this problem? A mix of both with heavy majority of renewables and nuclear/fossil only to guarantee baseloads seems like the best idea to me.
Disagree, it's just that the safe level is around 0.1% of current use (though I don't just mean use of fossil fuels for electricity, I mean *everything*).
Yes: the way we should think about that is that we do things like switch to trains and BEVs so we can afford to continue running airplanes while synthetic fuels are being put into production.
It's not going to reduce any time soon. Either way the reality is that sometimes fossil fuel power plants make sense, that's why they're still being built.
It's unsafe so it's never a good fit? That kind of reasoning is just noise. Unsafe for what? Compared to what? What alternatives, given the constraints, exist?
Finding something ideologically inconvenient doesn’t make it noise. There is simply no level of new carbon emissions which isn’t guaranteed to cause expensive problems around the world. That doesn’t mean we can’t switch everything instantly but that means we shouldn’t be building anything new which has a safe alternative — and in the case of electric power generation or cars, that’s especially clear because burning fossil fuels for that is more expensive so you’re paying extra to pollute more.
I don't find it ideologically inconvenient, I just don't think it's a realistic take. There are situations for power generation where fossil fuels are the only viable alternatives hence why I mentioned them. Now if you had infinite resources and infinite money then that's probably not true, but we don't live in a world like that.
but it's somewhat risky, since if the power goes out in winter, to first order, everyone dies. I think you'd always keep the generator on at low load, just in case.
Note that wind turbines at pole have not historically been very successful, maybe that will improve.
I presume the optimal solution is solid oxide fuel cells + renewables. Not complete science fiction, but not quite ready to do away with the diesel backup.
Everyone is politically motivated on this subject, and that's a good thing, because this is a political decision by default, where the "political" is comprised of is, the voting citizens. We can't let decisions like these be taken by unelected technocrats alone.
I'm not filled with joy about my chav ("redneck") neighbours weighing in on nuclear vs solar and climate change and national and international energy markets and power distribution...
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
Very few things are purely technical decisions. In this case, it’s about centralized vs. distributed electricity generation (or freedom vs. dependence if you want to state it that way). One of these options makes it much easier for the billionaire class to continue extracting money out of the people.
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.
> One of these options makes it much easier for the billionaire class to continue extracting money out of the people.
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.
>In this case, it’s about centralized vs. distributed electricity generation (or freedom vs. dependence if you want to state it that way).
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?
> people who act like renewables are "freeing" ... and the people who advocate nonstop for government management
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.
> People arguing for one alternative over the other are usually politically motivated.
If you can spend a Dollar only once, you might end up with renewables. People can be economically motivated too. No reason to draw politics in an already heated discussion.
I have not seen anyone arguing only nuclear to get rid of fossil fuels, what I see is people arguing that we need nuclear to supplement renewables to remove fossil fuel and the other side saying renewables and batteries(and maybe the occasional gas peaker plant or two...) or bust.
There are people who advocate for an all nuclear strategy but other than the ones whose non-profit gets fossil fuel industry contributions it seems to be much less common than a decade ago because the economics are undeniable now.
Nuclear power is massively subsidized already — those plants only get built with massive state support. Right now you can justify a solar rollout with traditional fins because it pays for itself in a couple of years but in the United States a new plant is subsidized at every step of the design and build, and fuel is subsidized from mining to disposal.
That’s the underlying problem: it’s not a question of whether nuclear can work at all ever but rather that for any given point since the early 2010s it’s been very hard to justify nuclear because you need to spend billions of dollars more than renewables upfront and accept higher CO₂ emissions for 1-2 decades before it makes any reduction in emissions. If we’d invested half a century ago like France it might’ve been very different but the cost and time differential now is so stark.
For this we can just use our old friend uptime. Solar downtime is always daily unless you're in the arctic. Nuclear power will be at least 2 nines. Battery and solar, that is the hardest variable to measure.
It can be, but you need water, just like for solar you need sunlight and storage and for wind power you need, well, wind. Coal and gas rely on natural resources, which can be disrupted through geopolitical tension, like Russia's gas supplies into Europe getting cut off / sanctioned.
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.
That’s like 0.3-5% per C° so even at extreme temperatures you’re talking like -15% — and that’s happening when it’s extremely sunny so you’re talking 85% or better, not a 15 point reduction off of an already limited panel. Nuclear costs so much more that renewables and batteries can be overprovisioned to compensate and still be massively cheaper, not to mention online a decade or more earlier.
Not true at all. It's both in France and increasingly because the rivers run dry in the summer. Besides killing rivers for electricity and for "saving CO2" is as stupid as burning coal to keep HVACs running becauae the summers are getting hotter and hotter each year.
This is a technical problem with technical solutions. You can just fix things, you don't need to throw out 30% of your power generation to pay billions for climate change vagueposting.
Kind of? I'm sure you can change a nuclear power plant so it doesn't rely on river or sea water but that's not something that can be done overnight.
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.
Electricity costs by nuclear power is heavily subsidized by tax money in France, so the French are paying the higher costs anyway. Just saying. Maybe there's a technical solution involving nuclear but it's really expensive compared to the much cheaper technical solution: renewable energy.
Of course a 1960's design isn't adapted to current weather conditions. That doesn't mean the whole technology is useless, like so many commenters imply.
Any new build can and will include cooling adapted to hotter conditions.
Hungary had the highest share of produced solar electricity of all the countries in the world 27.3%.
And even with this results nuclear energy is usefull for them and plan to build new reactors. (with help from Russia, so there may be same changes in this plan)
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.
Yes, absolutely colossal amounts of batteries though - what if it’s quite hot but also cloudy for 5 days in a row?
You either have to significantly oversize the PV (easier said than done, when its energy density is already not that high per m2), or have enough batteries to last for multiple days of full load. If you do the maths that’s a lot of batteries
>what if it’s quite hot but also cloudy for 5 days in a row?
The main idea is to then import power from somewhere sunny and/or windy or mountainous, using money you saved when they had the rain and you had the sun.
Batteries and other storage mechanisms will gradually reduce the need for doing so, but aiming to entirely eliminate all need for cooperation with others seems a bit paranoid.
"According to the adopted act, devices with a capacity of up to 30 kWh are exempt from any construction procedures; only reporting to the grid operator (OSD) is mandatory. Those between 30 kWh and 300 kWh in a building and 30 kWh and 2000 kWh freestanding are obliged to prepare a land development plan and make fire safety arrangements."
AFAIK the mountains are about as high as Wales? It looks like there's a 600MW storage scheme in the planning stages. That's about a third of the capacity of Wales's largest system (which is the biggest in Europe) and about twice the capacity of the second system.
It's a meaningful contribution I would have thought.
Can't speak for Hungary specifically, but the problem with flat terrain wrt hydro storage isn't just elevation difference - which can be offset with flowrate - it's the large surface area to storage and to depth ratios.
Large lake means more losses, mainly due to evaporation, but seepage is also to be expected. Now put this fact in the thread's context: water shortage/stress...
"Most of the country has an elevation of less than 200 m. Although Hungary has several moderately high ranges of mountains, those reaching heights of 300 m or more cover less than 2% of the country."
"Hydroelectricity is not prevalent in Hungary due to unsuitable geographical conditions and civil resentment. The country's capacity of hydroelectricity was 57 MWs in 2015."
It depends on the water balance.
Reservoirs would help you smooth out variability/seasonality and mitigate infrequent, short term droughts, depending on its size. They would not help with a long term drought or if you are water stressed (i.e. you simply don't have enough to meet demand). Quite the opposite, they may exasperate the issue as they consume (or lose) water themselves.
I'm fairly sure that when it's dark where I am (because I'm in the shadow cast by Earth), it's also dark in orbit above me (because it's in the shadow cast by Earth).
That math leaves out externalities when pricing gas, oil and coal. You may have heard of a few fires going on in Europe in addition to nuclear plants shutting down?
Beyond that, those resources are also the lifeline for a dictatorship in the east causing increase defense spending.
There definitely is no such thing as cheap gas, oil or coal for Europeans, all things considered
You're probably going to struggle to come up with a motive for that behaviour. It is much more likely that they simply aren't very thoughtful. Complex webs of deception in a public argument are certainly possible, but it generally relies on some group having a clear financial incentive to misdirect. That doesn't exist in the nuclear debate.
Because HN was a forum for oil executives to gather and discuss prices? Big fossil isn't in the room here. It would surprise nobody if there were 0 people in the comments who even work in a fossil fuel company.
>You're probably going to struggle to come up with a motive for that behaviour.
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.
>we cannot build them anywere in Europe due to plain stupidity.
Economics I think. Nuclear power has gone bankrupt in France already (arguably more than once) and gotten bailed out. Now they produce electricity at a price that's often above market price, with losses covered by the taxpayers.
This despite relying on cheap cooling from rivers. Adding more expensive cooling won't help.
We've quite recently reached mass production economies of scale for both solar panels and batteries. The implications are that the price of electricity is set to drop even more in the years to come.
The bad financial shape of EDF had multiple reasons:
1. Cost overruns in construction of the new EPR reactors. The EPR is a extremely safe and as a result extremely overengineered and expensive design. The aim was to merge the French N4 design and German Konvoi design and have a standard design which would satisfy nuclear regulators in all countries. France wants now to simplify EPR and build cheaper and simpler EPR2.
2. EDF was mandated to sell large part of it's electricity production at bellow the market value. The ARENH mechanism.
"The ARENH (which in French means “regulated access to historic nuclear energy”) was created in 2011 in the context of the opening of the electricity market to competition. The law that provided a framework for this opening-up had the main objective of enabling all consumers to benefit from the competitiveness of the French nuclear fleet. Before the ARENH, EDF was the main electricity supplier, covering 95% of the French territory (the rest being covered by local distribution companies). Under the ARENH, so-called alternative suppliers (i.e. other than EDF) obtained access to a regulated price (€42/MWh) for the electricity produced by EDF’s historic nuclear fleet within a volume limit of 100 TWh per year. This is equivalent to almost a third (27.64%) of 2024 French nuclear production (361.7 TWh)."
At this point in time it can be assumed that 90% of everything on the internet is a lie.
French nuclear electricity is cheap because the government subsidizes it to keep it afloat. And because continental European electricity is generally expensive. It probably wouldn't survive in a free market.
I believe this is why the USA recently declared that it's no longer going to follow the "linear no-threshold model" and "as low as reasonable achievable" principle of radiation exposure. In other words they're declaring that a small amount of radiation is good for you. Building a reactor without shielding and with a single open-cycle water loop should reduce costs, right?
(Do you know what else reduces costs? Apparently, putting a foot of graphite at the bottom of your control rods and not paying close attention to a dangerously unstable reactor during an unusual experiment. These aren't official American policy yet.)
Also, the USA's recent ban on solar electricity equipment should help make other forms more competitive.
Linear no-threshold and ALARA are pretty objectively overly conservative, to the point of potentially doing more harm than good (Fukushima is mentioned down below. More people died as a result of the evacuation than would have resulted from the radiation) as well as making many things obscenely expensive. It's a little absurd that nuclear plants obsess over radiation doses smaller than a short-haul flight.
Linear no-threshold being false doesn't necessarily mean a little bit of radiation is good for you, though there is some shaky data to suggest that might be true, just that small amounts of radiation are not as proportionally bad as large amounts.
Nobody from the Fukushima accident died from radiation sickness or radiation syndrome, and so far there's been no evidence of long term elevated cancer rates either.
Meanwhile the nuclear industry has been drowning for 50+ years from egregious layers of overregulation.
It costed NuScale $500+ Million just to write the documents required for regulatory approval for a new reactor design.
Microsoft is spending $60 Million a year to build an LLM whose only purpose is to automate writing nuclear regulatory documents.
I don't support the Trump admin one iota, but I'm also saddened that democrats tend to be too safetyist to do an honest cost benefit evaluation of some of these insane regulations.
>Nobody from the Fukushima accident died from radiation sickness or radiation syndrome, and so far there's been no evidence of long term elevated cancer rates either.
You say these two things as if the second statement supports the first, but it doesn't.
The dangers of radiation are very well known and don't change at all based on what happened at Fukushima. If you fire a gun and miss, the gun is still dangerous.
>Meanwhile the nuclear industry has been drowning for 50+ years from egregious layers of overregulation.
Here's an account of two gruesome deaths caused by poor regulation of nuclear materials in Japan. It happened 12 years before Fukushima.
People die from the operation & externalities of every energy source, it's just that Nuclear power has orders of magnitude fewer deaths per kilowatt-hour than the dirtier energy sources these regulations have pushed energy production towards.
I'm sure some lives would be lost if Nuclear Power faced the same regulatory costs that other energy sources do, rather than the egregious and absurd costs they face today.
But many many more lives would be saved by deregulating nuclear energy and making it more cost competitive with coal and natural gas.
Many children wouldn't contract asthma & the other respiratory illnesses they do today if nuclear energy hadn't been killed via overregulation and replaced by coal and natural gas.
I think you're seriously misunderstanding the statistic I posted.
I didn't post aggregate deaths from different power sources, I posted deaths per terawatt-hour of energy produced!
This figure includes deaths from every nuclear accident, and yet it shows getting energy from nuclear power is orders of magnitude safer than getting the same energy from the fossil fuels that have replaced nuclear power in countries that have phased them out. (like germany)
Most of the nuclear power that makes up that chart was built when there was significantly less regulation on reactors than there is today.
Even if deregulation increased nuclear deaths per watt by two orders of magnitude (which I strongly doubt!), nuclear would still be orders of magnitude safer than the fossil fuels that have replaced it across the western world.
Interesting but people die (or are severely injured) in all kinds of industrial accidents all the time. Unfortunately, with or without regulation it comes with the territory of a modern industrial society.
>Interesting but people die (or are severely injured) in all kinds of industrial accidents all the time.
Very few other industrial accidents cause effects that have to be dealt with for decades over 1000 miles away, even across oceans.
Nuclear power really is in a league of its own when it comes to risk. I am not aware of anything that comes close. Dam accidents have killed many more people and devastated towns, but the day after that happens, the area can be reused and the risk is entirely gone. The risks of nuclear power remain for decades or even centuries.
Finding ways to deal with that risk is fine, arguing that it can be managed is fine, but pretending that the risk is exaggerated based on the accidents that have happened so far is a mistake.
The risk is things that could happen, not what has actually happened.
There are estimates that pollution from European coal power plants cause more deaths EACH year in Europe, than the total estimated deaths from Chernobyl accidents (most pessimistic estimate 4000-8000 deaths).
For example, just the Great Smog event that affected London, England, in December 1952 caused by modern estimate 10,000–12,000 deaths.
>There are estimates that pollution from European coal power plants cause more deaths EACH year in Europe,
First and foremost - coal sucks.
Secondly - the choice isn't between nuclear or coal.
That said, the estimates you mention are not believable. Pollution as a whole causes lots of premature deaths, but coal burned in electricity plants are a very small part of total pollution.
Especially in Europe, where most countries no longer operate coal power plants. Not even the UK.
> Nobody from the Fukushima accident died from radiation sickness or radiation syndrome, and so far there's been no evidence of long term elevated cancer rates either.
"NuScale spent over $500 million, with the backing of Fluor, and over 2 million labor hours to develop the information needed to prepare its DCA application. The company also submitted 14 separate Topical Reports in addition to the over 12,000 pages for its DCA application and provided more than 2 million pages of supporting information for NRC audits."
How could writing code possibly cost that much? And yet tech companies spend significantly more than that per year on it. You need a lot of highly paid, experienced people to do it (negotiating regulatory frameworks is pretty much its own profession).
Solar panels decrease in efficiency when hot, but it's not like a complete shutdown.
When your solar panels are hot is noon in the summertime which is when you have way more solar power than you need anyway. Most grids that have substantial solar power are getting saturated with solar power at that time and running everything else at minimum capacity.
You can totally retrofit existing nuclear power plants for closed loop cooling. I'm not sure what the cost would be, though, but it might be worth doing.
Is it economically viable to run though? Natural draft towers or direct body of water cooling is used almost universally since it doesn't take any extra power. A large chunk of the powerplant's output would be running heat pump compressors to stop itself from exploding.
Fully closed loop is probably not viable. But I suspect that's not the extreme GP might have meant.
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
How do these things, whose sole purpose is to turn heat into electricity, end up with so much extra heat that it takes more energy than they produce to disperse it? Can't the excess heat in a closed loop system be captured and used to power the cooling? Sorry, maybe this is a stupid question.
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.
Wouldn’t a Carnot engine with 33% efficiency produce 2 J of heat per 1 J of mechanical work? With 40% efficiency 1.5 J of heat? Efficiency of the generator should be better than 90 % so I think the 3x estimate is a bit off.
The heat doesn't disappear. Useful work is heat, it's just that some of it is intercepted before final dissipation.
If you look at real-world numbers, you're generally going to see 3x the thermal output as electrical output from any thermal energy plant. Two-thirds of that thermal output is wasted, and you'd see your 2x figure there. But the useful electrical output eventually ends up as heat as well, whether in direct thermal applications, from mechanical applications, lighting, refrigeration, audio equipment, or electronics.
The (admittedly theoretical) numbers in this example show that:
Incidentally: this all-but-inevitably leads to an online hand-wringing about the inefficiency of energy systems when an energy flow chart (Sankey diagram) is released, showing a 2:1 "rejected energy" ratio. It turns out that that's not a measured quantity but a modeled quantity, if you read the fine print. The 2/3 loss is just physics, thermdynamics and Carnot as noted previously.
Well we are still discussing cooling of power plants. The part of the energy that goes into the grid cannot be used to heat the river. It turns into heat somewhere else.
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.
okay but to maybe beat a dead horse, if you have these enormous cooling towers spewing out steam, is the steam coming out the top of those just not economically viable to use to run smaller generators or something?
There are plants with multiple stages of turbines. You really do need high pressure, high temperature steam to make appreciable energy though. What comes off the top of a cooling tower will keep you warm, but it's had 99% of its energy already extracted.
The laws of thermodynamics don't allow it. Energy usually comes with entropy attached, which can't be destroyed and has to be dumped somewhere. At a colder temperature you need less energy to raise the entropy, which allows for energy and entropy to be split into a cold part (containing most of the entropy and some energy) and a hot part (containing low entropy) at specific ratios. Electricity is low-entropy energy, which is why it's so useful.
"Heat" is really entropy gain, and so in order to do useful work you have to increase the entropy of the system to higher and higher quantities. If you want to move entropy from one closed system to another(to cool one system down) then you must emplace even more entropy in the one system than you removed from the other because you must spend entropy(generate heat) in order to force a change in the state of the other system. It's a fundamental law of physics. You cannot reduce the entropy of the universe by any means.
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.
First of all you can't retrofit every npp with that, it's a lie. And eve; if you could, you are correct, it's financially not viable. Renewable energy is always the cheaper option by far.
I find it interesting the discussion here is entirely about water temperature whereas the shutdown is entirely about NPSH.
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.
I ask once again: why is everyone so convinced that nuclear is the one technology that somehow doesn't get cheaper and better with advancing tech and scale? And don't tell me learning curves are proven to not apply. The preconditions for learning curves are arguably only now being met in China.
What do you consider adequate cooling? Remember that for every GW of electricity you need to remove 2-3 GW of heat. That's a lot of heat. Strapping a giant PC radiator fan to the plant won't cut it.
That seems like a huge disadvantage for nuclear power if you need to guarantee strict ideological commitment to ignore cost-competitiveness not just now but into the future. Renewables and batteries are not only cheaper now but have far less scope for major failures based on some MBA cutting corners in a decade.
A nuclear plant being forced offline by low river levels is a striking reminder that even low-carbon energy depends on climate-resilient infrastructure. How many plants across Europe face the same cooling-water risk?
They also constantly criticise Germany and its nuclear power plant closures, linking almost every negative news story about the country to this issue. It seems they’re completely unaware of the potential consequences of operating a nuclear power plant.
A lot of energy crisis in Germany is due to the closure of their power plants. Just like any other infrastructure, nuclear power plants needs to be modernised over the time and Hungary didn’t do that. It’s not the fault of nuclear technology, but lack of management in Hungary’s case
Every power source has trade offs, bud. They call solar renewable, but in fact panels have a shelf life, and take valuable finite resources and energy to manufacture. This is what climate change activists like to ignore /s
Here in Switzerland during some heatwaves they have to shut down nuclear plants too because the river water is too warm and adding warm water to it would kill the fish.
And it's not cold enough to cool the reactor
The reactor absolutely is not going to care, it’s the tertiary cooling circuit cooling for the steam turbines, it will have cooked off everything downstream long before it’s an issue.
This is entirely an ecological and safety concern.
The principle cooling mechanism is vapourisation.
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.
Backing this up, these high numbers are for typical cooling towers where they vent to atmosphere.
Once you get into closed loop PWRs the numbers get crazy. Actual figures for Naval Nuclear plants are classified, but as a nice round number example if you pressurize the secondary loop to 250psi you end up with about 1,725 kJ/kilogram to boil it.
Absolutely terrifying stuff.
One of us seems to have our numbers wrong.
1,725 kJ/kg is 1,725 J/g, which is less than the enthalpy of vapourisation I'd quoted.
(Though yes, I understand your point: pressurisation raises boiling point, and so far as I'm aware, vapourisation energy.)
Probably me. I wrote that on the train...
No that's never the problem, even 40°C intake is cool enough to cool a reactor, it's all just a question of returned water temperature that can be harmful to a river if too high (generally the limit in Europe is set to 30°C).
It can vary by the river too (e.g. I remember Switzerland pulling back a reactor around 25 intake), and iirc there’s an absolute limit on the outflow (you don’t want to boil alive the stuff just off of the plant) and a relative one a bit downstream (you can’t heat the river to 20 when it’s freezing).
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.
As long as it’s designed for those temperatures everything is fine, but efficiency still suffers.
Absolutely wrong. A difference of a couple degrees is not going to hamper cooling a reactor that is running at many hundred degrees.
Just imagine what it would spell for your car otherwise.
I think both nuclear steam and car engines are affected by high ambient temp, gas and coal engines too.
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.
Convection cooling efficiency is mostly dictated by the delta in temperature between the hot and cold source. Coolant temperature in the core is in the 300C ballpark. So the river going from 20 to 30C is roughly a 0.3% change in cooling efficiency.
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.
Begs the question: coul reactors use radiative air cooling? Channel the water through a huge radiator and transfer the heat to the air
The temperatures aren't high enough to do that (or air cooling) efficiently enough. Some experimental designs for high temperature operation would have that as a possibility (e.g. molten salt reactor designs). I think a Chinese research project is looking into air cooling for nuclear power in dry regions.
There's also the potential of co-locating non-evaporative cooling with CO2-scrubbing using a strong KOH solution in the big cooling towers and regenerating the hydroxide with calcium hydroxide (regular process done in kraft process paper mills, though they use NaOH with slightly favoured properties over KOH). KOH is very hygroscopic; it does not have to be humid for a barely-still-liquid solution to actually dehumidify in the process.
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.
Not really, a large reactor is way too power dense. An EPR reactor has a thermal output of 4.6GW. And the tertiary is cooling steam turbines so it's below boiling, you'd need something like 10 sqkm worth of surface, per reactor, with an environment cool enough that this could actually radiate.
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)
Mochovce nuclear power plant, with evaporative cooling towers, uses around 21.6 to 24.8 million m³ per year depending on operating units and seasonal weather demands. (About 0.7 m³ per second)
https://www.seas.sk/wp-content/uploads/a3/b4/2023_SE_NPP_ENG...
The German THTR-300 reactor operated with air cooling:
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.
OP is correct, the people making fun of OP don't have an engineering background.
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...
Lol no. Latent heat is basically all that matters
Would a cooling pond with controlled discharge into the river maybe mitigate this problem? One could also cycle the water from the cooling pond through the plant's cooling loop. The worse that could happen is evaporate the water from the cooling pond which is gets replaced with new water (sans fish) from the river.
> Would a cooling pond with controlled discharge...
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.
Nuclear plants can run with those hyperboloid cooling towers as the sink for waste heat. They are just a lot more expensive to build, run and maintain compared to using river water.
You still need water when cooling with towers. Instead of heating the river you consume some of its water and release it into the atmosphere.
Not TOO much loss tho, right?
I thought the cooling tower design helped maximize cooling and minimize loss as steam.
You try to maximalize evaporation. Evaporating water removes heat very efficiently with relatively small amount of water loss.
Short introduction into cooling towers:
https://m.youtube.com/watch?v=tmbZVmXyOXM
making modern websites not 100's of megabytes heavy would go a long way
FWIW, this one was only about 5 MB.
The images related to the article are about 0.5MB.
There's plenty of work happening with adapting non evaporative cooling loops for data centers. Maybe that can be applied here too, even if to mitigate some of the cooling needed?
Data centers can afford to spend way more per kWh of heat discharged. Nuclear needs to dump 3+kWh of heat per kWh of electricity generated.
Nitpick here:
Nuclear discharges more like 2kWh of heat per kWh of electricity produced.
Perhaps slightly more, but its in that ballpark. Seems like a small difference but you are overstating the waste by near 50%.
Source: Degree in Nuclear Engineering, previous life was a Reactor Operator. Also, just look up thermal efficiency of currently operating reactors.
That 3+:1 is actually from being pedantic.
2:1 implies 33% thermal efficiency to the grid which is commonly achieved in normal operations.
Unfortunately engineering means you can’t work with such overly simplified models. Many ways of dumping heat run into issues from solar gain prevents dumping significant heat under the employe parking lot etc.
I don't disagree but am having a hard time parsing the second half of your comment.
In my experience we saw some losses when taken as a system that prevented us from hitting 2:1, but they weren't anywhere near 50%. We also ran closer to 40% than 33% thermal efficiency in the power generating loop, so many of the system thermal costs are baked into that 33% efficiency to the grid.
Basically, each reactor install will have it's own minor issues. Overall they should be hitting around 2:1 as an entire system. If they aren't there is something going on that I haven't come into contact with (which is quite a lot, I'm sure).
> hard time parsing the second half of your comment.
I’ll put it as a spherical cow engineering problem. Let’s suppose the temperature is 30C and you want to dissipate 2GW of heat across a 1kmx1km flat plate, what temperature will it get? That’s a relatively straightforward calculation if you don’t need high precision.
However in the real world it wouldn’t have a single equilibrium temperature. 30C at night the heatsink would be one temperature and in the daytime it would be a different temperature due to sunlight.
Evaporative cooling largely sidesteps this issue, but it’s worth keeping in mind why that’s chosen over other seemingly cheaper options.
This is happening all across Europe right now - Romania, France too.
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.
People arguing for one alternative over the other are usually politically motivated. I feel like you are doing the same. Sometimes nuclear is a good fit, sometimes renewables is a good fit, sometimes fossil fuels are a good fit. Most of the time a mix is the best fit. It depends on what you are optimizing for and what is geographically, (geo)politically and economically possible. All these systems are then built using assumptions, sometimes those assumptions no longer make sense after a certain period of time and sometimes you just temporarily or permanently have to adapt to the changes in the environment. This is an unusual but expected scenario for the nuclear plants along the Danube.
I'm not really opposed to nuclear power politically. I just think it's a non-starter given the much higher cost, complexity of buildout and lack of reliability.
In countries with dark winters and without enough hydro power, the only reliable alternative are fossil fuels...
Wind + storage, geothermal.
Storage of energy in the dimensions required for weeks with almost no wind is an unsolved problem. Right now, we can't store enough to make it through a single night without using fossil fuels. Most countries don't even have the capacity to store the energy for a single hour.
As we can store fossil fuels for weeks of demand, we can store the required energy in chemical form, no? Germany has huge natural gas storage, for ezample.
If you mean hydrogen, this video explains the issues better than I can: https://www.youtube.com/watch?v=Zklo4Z1SqkE
Doesn't need to be hydrogen - plenty of possible substances that could be used as storage (might not even need to be gaseous for some applications).
Geothermal and storage is worth investing in, investing in nuclear is not. NPPs are simply too expensive and you won't find investors unless you heavily subsidize it with tax money. Only compnies willing to invest in NPPs are those with virtually free money: the handful of AI big tech giants.
How can you be sure of that before even having a practical and proven solution for the required scale of storage?
We have proven solutions.
We're building the factories to make them as fast as we can find investors with money to spend on them, because they're already cheaper than fossil fuels which are themselves cheaper than nuclear.
Iceland has no nuclear power plants.
Iceland is a small area, small population outlier literally sitting on two plates rubbing up against each other and a relative excess of active volcanism and large lava fields.
~ https://en.wikipedia.org/wiki/IcelandWhat works for Iceland works in few other places to the same degree (New Zealand, Yellowstone, places with thin crust and feisty caldera's).
Germany also has potential for 85% geothermal energy.
There are some interesting spots here but it's generally enough through the country to do it everywhere.
Munich gets quite a lot of it's energy from geothermal sources
Countries like UK, Ireland, Germany, Danmark, Netherland, Poland also have dark winters. Solar in winter is only about a fifth of production in summer months.
Iceland has geothermal, which is amazing, but won't help central Europe.
Those places also have a huge wind resource in the form of the North Sea, for Ireland whatever the other bits of that submerged continental shelf are called, and for Poland the Baltic: https://globalwindatlas.info/en/
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
Yet there are whole weeks practically without wind in winter. And most climate models estimate that global warming reduces wind further. Storage in the required dimensions is an unsolved problem.
> Yet there are whole weeks practically without wind in winter. And most climate models estimate that global warming reduces wind further.
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.
> The Atlantic continental shelf isn't correlated with the Baltic.
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
Max comment nesting reached. Instead of going through your response one by one, let me just say one thing: the premise and promise of the whole energy transition are based on studies that completely underestimated the physical and engineering challenges in practice. That's why we are where we are. Energy costs have gone up; CO2 emissions have not. I wouldn't believe any study before it has been implemented at scale, at least in a region or small country.
> How do you transmit the power?
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*:
And then linked you to a document, with a quote from that document, about using coal mines. The document you replied to with doubts, supports the conclusion you've just denied.Also, I already saw all of Tom Scott's videos when they were new. As per the document:
Storage in the required dimensions is an unsolved problem.
No, it's not. Decommissioned nuclear plant infrastructure used as massive battery storage.
https://gesi-deutschland.de/en/gesi-project-presented-in-gro...
870 MWh? It would take about 500 of them to make it through a 1-2 week dunkelflaute.
Why do you think that's a criticism?
- page 8, https://www.eionet.europa.eu/etcs/etc-cme/products/etc-cme-r...He/she said no reliable alternatives.
Agreed, whenever I hear someone say "we need more/less nuclear and less/more solar/wind", I hear "let's burn more fossil fuels while we uselessly split hairs".
Unless the scenario is totally different where you live, pro-nuclears are mainly "we need more nuclear, less rerewables, don't care about fossils, just guaranteed production", while pro-renewables are mainly "we need more renewables, less or no fossils and as few nuclear as possible".
If someone is getting wiped from the mix because of renewables, it is coal and fuel, not nuclear.
What about Germany?
The point they are making is that climate change will further push these conditions, so are we willing to build more nuclear power plants, knowing that by the time they are ready to go online this problem will be worse? Or better to invest in renewables which can be implemented today and will alleviate this problem? A mix of both with heavy majority of renewables and nuclear/fossil only to guarantee baseloads seems like the best idea to me.
> sometimes fossil fuels are a good fit
There is simply NO safe level of fossil fuel use.
Disagree, it's just that the safe level is around 0.1% of current use (though I don't just mean use of fossil fuels for electricity, I mean *everything*).
There’s applications that we still have no alternative for though - e.g. aviation - so we’ll have to accept the burning of hydrocarbons there.
Not fossil hydrocarbons forever, of course, but synthetic kerosene might be a thing soon enough.
Yes: the way we should think about that is that we do things like switch to trains and BEVs so we can afford to continue running airplanes while synthetic fuels are being put into production.
I don't know what you mean with "no safe level of fossil fuel use". It doesn't mean anything without contextualizing that statement.
There is already too much carbon in the atmosphere.
It's not going to reduce any time soon. Either way the reality is that sometimes fossil fuel power plants make sense, that's why they're still being built.
i thought it was pretty clear, personally.
It's unsafe so it's never a good fit? That kind of reasoning is just noise. Unsafe for what? Compared to what? What alternatives, given the constraints, exist?
Finding something ideologically inconvenient doesn’t make it noise. There is simply no level of new carbon emissions which isn’t guaranteed to cause expensive problems around the world. That doesn’t mean we can’t switch everything instantly but that means we shouldn’t be building anything new which has a safe alternative — and in the case of electric power generation or cars, that’s especially clear because burning fossil fuels for that is more expensive so you’re paying extra to pollute more.
I don't find it ideologically inconvenient, I just don't think it's a realistic take. There are situations for power generation where fossil fuels are the only viable alternatives hence why I mentioned them. Now if you had infinite resources and infinite money then that's probably not true, but we don't live in a world like that.
> There are situations for power generation where fossil fuels are the only viable alternatives
That doesn't make them safe. Eventually there situations will have to find a way to do without fossil fuels if we want to keep this planet habitable.
I don't see how that's relevant, my original post made no safety claims.
>sometimes fossil fuels are a good fit.
Oh come on.
Your at the north pole ... its dark all day long (and cold) ... you need some heat and some power
Scott base in Antarctica (NZ's scientific research base) is installing wind turbines and batteries and getting rid of diesel generators.
Yes but the South Pole burns jet fuel. Not much wind and 6 months of darkness.
The hut point peninsula is consistently windy though and the turbines are pretty! https://photos.app.goo.gl/goDVb7KuiKr6soHT6
So, larger batteries, then. Or produce hydrogen from excess wind power in the summer as a chemical battery.
yes, people (some of whom I know) have looked at this of course: https://www.sciencedirect.com/science/article/pii/S136403212...
but it's somewhat risky, since if the power goes out in winter, to first order, everyone dies. I think you'd always keep the generator on at low load, just in case.
Note that wind turbines at pole have not historically been very successful, maybe that will improve.
I presume the optimal solution is solid oxide fuel cells + renewables. Not complete science fiction, but not quite ready to do away with the diesel backup.
Everyone is politically motivated on this subject, and that's a good thing, because this is a political decision by default, where the "political" is comprised of is, the voting citizens. We can't let decisions like these be taken by unelected technocrats alone.
I'm not filled with joy about my chav ("redneck") neighbours weighing in on nuclear vs solar and climate change and national and international energy markets and power distribution...
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
Plot twist, the experts are lobbyists and they convince our politicians to start fracking and massively increase the use of "clean coal"
I would be willing to bet on a board of PHDS of varying sciences they would determine that coal is dumb and a waste of money
there are plenty of PHDs out there who have been bought and are in the pockets of industry...
>and that's a good thing, because this is a political decision by default,
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?
Very few things are purely technical decisions. In this case, it’s about centralized vs. distributed electricity generation (or freedom vs. dependence if you want to state it that way). One of these options makes it much easier for the billionaire class to continue extracting money out of the people.
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.
> One of these options makes it much easier for the billionaire class to continue extracting money out of the people.
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.
>In this case, it’s about centralized vs. distributed electricity generation (or freedom vs. dependence if you want to state it that way).
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?
> people who act like renewables are "freeing" ... and the people who advocate nonstop for government management
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.
> People arguing for one alternative over the other are usually politically motivated.
If you can spend a Dollar only once, you might end up with renewables. People can be economically motivated too. No reason to draw politics in an already heated discussion.
> It depends on what you are optimizing for and what is geographically, (geo)politically and economically possible.
I mentioned all of this in my message. What was unclear about it or did you perhaps not read past the first sentence?
I have not seen anyone arguing only nuclear to get rid of fossil fuels, what I see is people arguing that we need nuclear to supplement renewables to remove fossil fuel and the other side saying renewables and batteries(and maybe the occasional gas peaker plant or two...) or bust.
There are people who advocate for an all nuclear strategy but other than the ones whose non-profit gets fossil fuel industry contributions it seems to be much less common than a decade ago because the economics are undeniable now.
This seems like a strawmen. Most nuclear advocates I see online just want nuclear power given the same subsidies and chances that PV/Wind get.
Nuclear power is massively subsidized already — those plants only get built with massive state support. Right now you can justify a solar rollout with traditional fins because it pays for itself in a couple of years but in the United States a new plant is subsidized at every step of the design and build, and fuel is subsidized from mining to disposal.
That’s the underlying problem: it’s not a question of whether nuclear can work at all ever but rather that for any given point since the early 2010s it’s been very hard to justify nuclear because you need to spend billions of dollars more than renewables upfront and accept higher CO₂ emissions for 1-2 decades before it makes any reduction in emissions. If we’d invested half a century ago like France it might’ve been very different but the cost and time differential now is so stark.
For this we can just use our old friend uptime. Solar downtime is always daily unless you're in the arctic. Nuclear power will be at least 2 nines. Battery and solar, that is the hardest variable to measure.
It can be, but you need water, just like for solar you need sunlight and storage and for wind power you need, well, wind. Coal and gas rely on natural resources, which can be disrupted through geopolitical tension, like Russia's gas supplies into Europe getting cut off / sanctioned.
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.
You dont even need a huge amount of water with the right closed-cooling-cycle reactors. High Temperature Gas Cooled Reactors for example.
It’s the second of third year in a row that this happens.
At some point it will be the new normal.
https://telex.hu/belfold/2026/07/31/energia-krizishelyzet-ho...
High temperatures also severely affect solar panel efficiency.
That’s like 0.3-5% per C° so even at extreme temperatures you’re talking like -15% — and that’s happening when it’s extremely sunny so you’re talking 85% or better, not a 15 point reduction off of an already limited panel. Nuclear costs so much more that renewables and batteries can be overprovisioned to compensate and still be massively cheaper, not to mention online a decade or more earlier.
Nuclear power plants can be equipped with cooling towers so the heated water doesnt go back to the danube directly.
Different reasons though, France has nothing to do with water level or availability. It's for environment protection.
Not true at all. It's both in France and increasingly because the rivers run dry in the summer. Besides killing rivers for electricity and for "saving CO2" is as stupid as burning coal to keep HVACs running becauae the summers are getting hotter and hotter each year.
This is a technical problem with technical solutions. You can just fix things, you don't need to throw out 30% of your power generation to pay billions for climate change vagueposting.
Kind of? I'm sure you can change a nuclear power plant so it doesn't rely on river or sea water but that's not something that can be done overnight.
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.
Electricity costs by nuclear power is heavily subsidized by tax money in France, so the French are paying the higher costs anyway. Just saying. Maybe there's a technical solution involving nuclear but it's really expensive compared to the much cheaper technical solution: renewable energy.
I wonder if any new hunger stones have been found since the Danube's wafer level reached this new record low.
https://en.wikipedia.org/wiki/Hunger_stone
They found mamooth bones!
Edit: add source [ger] https://science.orf.at/stories/3236752/
Of course a 1960's design isn't adapted to current weather conditions. That doesn't mean the whole technology is useless, like so many commenters imply.
Any new build can and will include cooling adapted to hotter conditions.
There's a nuclear reaction in the sky beaming free energy to us, let's just use that
According to solar statistics by country in 2025:
https://en.wikipedia.org/wiki/Solar_power_by_country
Hungary had the highest share of produced solar electricity of all the countries in the world 27.3%. And even with this results nuclear energy is usefull for them and plan to build new reactors. (with help from Russia, so there may be same changes in this plan)
Hungary is already using that (today we were 90% carbon-free thanks to solar), the problem is what to do when it gets dark.
Batteries?
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.
Yes, absolutely colossal amounts of batteries though - what if it’s quite hot but also cloudy for 5 days in a row?
You either have to significantly oversize the PV (easier said than done, when its energy density is already not that high per m2), or have enough batteries to last for multiple days of full load. If you do the maths that’s a lot of batteries
>what if it’s quite hot but also cloudy for 5 days in a row?
The main idea is to then import power from somewhere sunny and/or windy or mountainous, using money you saved when they had the rain and you had the sun.
Batteries and other storage mechanisms will gradually reduce the need for doing so, but aiming to entirely eliminate all need for cooperation with others seems a bit paranoid.
They're being installed but it's going to take a while.
Much faster than any nuclear build though.
Sure, but it doesn't solve today's problem with the low Danube.
In Poland you cannot own big capacity storage because it makes you independent from the grid and Gov does not want that.
So you can have storage, but not too much, only as much to still be dependant on the grid.
See the hypocrisy here?
You are not allowed to have own PV and big capacity storage without connection to electric grid?
You cannot have big storage either way. Its normal to have two installations and be able to switch between them.
Not in Poland, because you are too independent.
The legislation was updated:
"According to the adopted act, devices with a capacity of up to 30 kWh are exempt from any construction procedures; only reporting to the grid operator (OSD) is mandatory. Those between 30 kWh and 300 kWh in a building and 30 kWh and 2000 kWh freestanding are obliged to prepare a land development plan and make fire safety arrangements."
https://renewablesnow.com/news/poland-adopts-rules-to-ease-e...
Mechanical ones so we aren’t left with a waste disaster in 10-20 years?
"the problem is what to do when it gets dark"
Batteries (or pumped storage hydro, which is more like a gravity-driven capacitor)
Hungary is flat as hell, there's nowhere to build enough hydro storage.
But yeah batteries would be nice.
AFAIK the mountains are about as high as Wales? It looks like there's a 600MW storage scheme in the planning stages. That's about a third of the capacity of Wales's largest system (which is the biggest in Europe) and about twice the capacity of the second system.
It's a meaningful contribution I would have thought.
You can do low(er) head pumped hydro storage [0]
[0] https://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power...
Can't speak for Hungary specifically, but the problem with flat terrain wrt hydro storage isn't just elevation difference - which can be offset with flowrate - it's the large surface area to storage and to depth ratios.
Large lake means more losses, mainly due to evaporation, but seepage is also to be expected. Now put this fact in the thread's context: water shortage/stress...
Hungary is very flat.
"Most of the country has an elevation of less than 200 m. Although Hungary has several moderately high ranges of mountains, those reaching heights of 300 m or more cover less than 2% of the country."
https://en.wikipedia.org/wiki/Geography_of_Hungary
"Hydroelectricity is not prevalent in Hungary due to unsuitable geographical conditions and civil resentment. The country's capacity of hydroelectricity was 57 MWs in 2015."
https://en.wikipedia.org/wiki/Hydroelectricity_in_Hungary
> Now put this fact in the thread's context: water shortage/stress…
But doesn't adding a large reservoir mitigate both? You're not pumping the entire reservoir up and down hill every day.
It depends on the water balance. Reservoirs would help you smooth out variability/seasonality and mitigate infrequent, short term droughts, depending on its size. They would not help with a long term drought or if you are water stressed (i.e. you simply don't have enough to meet demand). Quite the opposite, they may exasperate the issue as they consume (or lose) water themselves.
Collect solar power in orbit (where sunlight is uninterrupted) and microwave[0] it to earth.
[0] https://en.wikipedia.org/wiki/Wireless_power_transfer#Microw...
I'm fairly sure that when it's dark where I am (because I'm in the shadow cast by Earth), it's also dark in orbit above me (because it's in the shadow cast by Earth).
[dead]
Calling the sun’s fusion "a nuclear reaction" in a discussion about fission reactors is a bit silly.
> let's just use that
Also, let’s use both?
It's not matter of "can", it's a matter of "how much does it cost?" and "who pays for that?".
Precisely why the Netherlands does not have nuclear power plants. Cheap coal. Cheap oil. Cheap gas. And now cheap wind and solar.
They just absolutely cannot math the math which leaves ideology and this ain't France.
https://en.wikipedia.org/wiki/Nuclear_power_in_the_Netherlan...
That math leaves out externalities when pricing gas, oil and coal. You may have heard of a few fires going on in Europe in addition to nuclear plants shutting down?
Beyond that, those resources are also the lifeline for a dictatorship in the east causing increase defense spending.
There definitely is no such thing as cheap gas, oil or coal for Europeans, all things considered
The one that shut down in Romania is a CANDU, built in the 80s.
More like a CANNOTDU ;)
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You're probably going to struggle to come up with a motive for that behaviour. It is much more likely that they simply aren't very thoughtful. Complex webs of deception in a public argument are certainly possible, but it generally relies on some group having a clear financial incentive to misdirect. That doesn't exist in the nuclear debate.
> a clear financial incentive to misdirect. That doesn't exist in the nuclear debate.
It's very obviously not in the interests of "big fossile" to go either solar or nuclear.
Because HN was a forum for oil executives to gather and discuss prices? Big fossil isn't in the room here. It would surprise nobody if there were 0 people in the comments who even work in a fossil fuel company.
>You're probably going to struggle to come up with a motive for that behaviour.
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.
Where have all the "what do you do when the wind doesn't blow and the sun doesn't shine" commenters gone?
Where are the comments about „molten-salt reactors dont need any of that”.
And a closed water loop. China builds them on a desert and we cannot build them anywere in Europe due to plain stupidity.
>we cannot build them anywere in Europe due to plain stupidity.
Economics I think. Nuclear power has gone bankrupt in France already (arguably more than once) and gotten bailed out. Now they produce electricity at a price that's often above market price, with losses covered by the taxpayers.
This despite relying on cheap cooling from rivers. Adding more expensive cooling won't help.
We've quite recently reached mass production economies of scale for both solar panels and batteries. The implications are that the price of electricity is set to drop even more in the years to come.
The bad financial shape of EDF had multiple reasons:
1. Cost overruns in construction of the new EPR reactors. The EPR is a extremely safe and as a result extremely overengineered and expensive design. The aim was to merge the French N4 design and German Konvoi design and have a standard design which would satisfy nuclear regulators in all countries. France wants now to simplify EPR and build cheaper and simpler EPR2.
2. EDF was mandated to sell large part of it's electricity production at bellow the market value. The ARENH mechanism.
"The ARENH (which in French means “regulated access to historic nuclear energy”) was created in 2011 in the context of the opening of the electricity market to competition. The law that provided a framework for this opening-up had the main objective of enabling all consumers to benefit from the competitiveness of the French nuclear fleet. Before the ARENH, EDF was the main electricity supplier, covering 95% of the French territory (the rest being covered by local distribution companies). Under the ARENH, so-called alternative suppliers (i.e. other than EDF) obtained access to a regulated price (€42/MWh) for the electricity produced by EDF’s historic nuclear fleet within a volume limit of 100 TWh per year. This is equivalent to almost a third (27.64%) of 2024 French nuclear production (361.7 TWh)."
https://hayaenergy.com/blog-end-of-french-nuclear-procuremen...
> Now they produce electricity at a price that's often above market price
Do you have any source? I'm not french and all I can hear from the news is that France's nuclear electricity is cheap, for example:
https://thenextweb.com/news/france-energy-advantage-ai-data-...
Now I'm curious what the truth is. Are these articles just fake-news trying to ride the AI wave? (not suggesting, just asking)
>Do you have any source?
There are many sources and it's of course complicated, but around 6 eurocents per kWh seems to be an accepted semi-official figure.
"The full cost of existing nuclear power calculated by the CRE amounts to respectively €60.7/MWh"
(https://www.enerdata.net/publications/daily-energy-news/fran...)
One can also deduce that it's somewhere between the old ARENH price of 4 cents (which is known to be unsustainable) and the new price of 7 cents.
Prices for wholesale electricity in the FR region have dipped below 5 cents (monthly average) several times in recent years. (Source: Nordpool).
At this point in time it can be assumed that 90% of everything on the internet is a lie.
French nuclear electricity is cheap because the government subsidizes it to keep it afloat. And because continental European electricity is generally expensive. It probably wouldn't survive in a free market.
Free market probably means they rely on Russian gas or coal from other countries ? Sometimes it’s worth paying a bit more to be independent
Solar panels keep getting better and cheaper every year. Can't say the same for nuclear.
A nice way to guarantee that is not not try.
I believe this is why the USA recently declared that it's no longer going to follow the "linear no-threshold model" and "as low as reasonable achievable" principle of radiation exposure. In other words they're declaring that a small amount of radiation is good for you. Building a reactor without shielding and with a single open-cycle water loop should reduce costs, right?
(Do you know what else reduces costs? Apparently, putting a foot of graphite at the bottom of your control rods and not paying close attention to a dangerously unstable reactor during an unusual experiment. These aren't official American policy yet.)
Also, the USA's recent ban on solar electricity equipment should help make other forms more competitive.
Linear no-threshold and ALARA are pretty objectively overly conservative, to the point of potentially doing more harm than good (Fukushima is mentioned down below. More people died as a result of the evacuation than would have resulted from the radiation) as well as making many things obscenely expensive. It's a little absurd that nuclear plants obsess over radiation doses smaller than a short-haul flight.
Linear no-threshold being false doesn't necessarily mean a little bit of radiation is good for you, though there is some shaky data to suggest that might be true, just that small amounts of radiation are not as proportionally bad as large amounts.
The harms of radiation are massively overhyped.
Nobody from the Fukushima accident died from radiation sickness or radiation syndrome, and so far there's been no evidence of long term elevated cancer rates either.
Meanwhile the nuclear industry has been drowning for 50+ years from egregious layers of overregulation.
It costed NuScale $500+ Million just to write the documents required for regulatory approval for a new reactor design.
Microsoft is spending $60 Million a year to build an LLM whose only purpose is to automate writing nuclear regulatory documents.
I don't support the Trump admin one iota, but I'm also saddened that democrats tend to be too safetyist to do an honest cost benefit evaluation of some of these insane regulations.
>The harms of radiation are massively overhyped.
>Nobody from the Fukushima accident died from radiation sickness or radiation syndrome, and so far there's been no evidence of long term elevated cancer rates either.
You say these two things as if the second statement supports the first, but it doesn't.
The dangers of radiation are very well known and don't change at all based on what happened at Fukushima. If you fire a gun and miss, the gun is still dangerous.
>Meanwhile the nuclear industry has been drowning for 50+ years from egregious layers of overregulation.
Here's an account of two gruesome deaths caused by poor regulation of nuclear materials in Japan. It happened 12 years before Fukushima.
https://science.howstuffworks.com/hisashi-ouchi.htm
https://ourworldindata.org/grapher/death-rates-from-energy-p...
People die from the operation & externalities of every energy source, it's just that Nuclear power has orders of magnitude fewer deaths per kilowatt-hour than the dirtier energy sources these regulations have pushed energy production towards.
I'm sure some lives would be lost if Nuclear Power faced the same regulatory costs that other energy sources do, rather than the egregious and absurd costs they face today.
But many many more lives would be saved by deregulating nuclear energy and making it more cost competitive with coal and natural gas.
Many children wouldn't contract asthma & the other respiratory illnesses they do today if nuclear energy hadn't been killed via overregulation and replaced by coal and natural gas.
>Nuclear power has orders of magnitude fewer deaths per kilowatt-hour
By this logic the minuteman missile is harmless. It hasn’t killed anyone, right?
Nuclear power has the potential to cause orders of magnitude more damage than any other power plant.
Again, what has happened is irrelevant, the risk is all about what could happen.
I think you're seriously misunderstanding the statistic I posted.
I didn't post aggregate deaths from different power sources, I posted deaths per terawatt-hour of energy produced!
This figure includes deaths from every nuclear accident, and yet it shows getting energy from nuclear power is orders of magnitude safer than getting the same energy from the fossil fuels that have replaced nuclear power in countries that have phased them out. (like germany)
Where would unregulated nuclear power go on that chart?
Most of the nuclear power that makes up that chart was built when there was significantly less regulation on reactors than there is today.
Even if deregulation increased nuclear deaths per watt by two orders of magnitude (which I strongly doubt!), nuclear would still be orders of magnitude safer than the fossil fuels that have replaced it across the western world.
Interesting but people die (or are severely injured) in all kinds of industrial accidents all the time. Unfortunately, with or without regulation it comes with the territory of a modern industrial society.
>Interesting but people die (or are severely injured) in all kinds of industrial accidents all the time.
Very few other industrial accidents cause effects that have to be dealt with for decades over 1000 miles away, even across oceans.
Nuclear power really is in a league of its own when it comes to risk. I am not aware of anything that comes close. Dam accidents have killed many more people and devastated towns, but the day after that happens, the area can be reused and the risk is entirely gone. The risks of nuclear power remain for decades or even centuries.
Finding ways to deal with that risk is fine, arguing that it can be managed is fine, but pretending that the risk is exaggerated based on the accidents that have happened so far is a mistake.
The risk is things that could happen, not what has actually happened.
You probably mean the Chernobyl accident.
There are estimates that pollution from European coal power plants cause more deaths EACH year in Europe, than the total estimated deaths from Chernobyl accidents (most pessimistic estimate 4000-8000 deaths).
For example, just the Great Smog event that affected London, England, in December 1952 caused by modern estimate 10,000–12,000 deaths.
https://en.wikipedia.org/wiki/Great_Smog_of_London
>There are estimates that pollution from European coal power plants cause more deaths EACH year in Europe,
First and foremost - coal sucks. Secondly - the choice isn't between nuclear or coal.
That said, the estimates you mention are not believable. Pollution as a whole causes lots of premature deaths, but coal burned in electricity plants are a very small part of total pollution.
Especially in Europe, where most countries no longer operate coal power plants. Not even the UK.
> Nobody from the Fukushima accident died from radiation sickness or radiation syndrome, and so far there's been no evidence of long term elevated cancer rates either.
There has actually been 1 radiation death
How can writing documents possibly cost $500,000,000?
https://www.nuscalepower.com/press-releases/2020/nuscale-pow...
"NuScale spent over $500 million, with the backing of Fluor, and over 2 million labor hours to develop the information needed to prepare its DCA application. The company also submitted 14 separate Topical Reports in addition to the over 12,000 pages for its DCA application and provided more than 2 million pages of supporting information for NRC audits."
How could writing code possibly cost that much? And yet tech companies spend significantly more than that per year on it. You need a lot of highly paid, experienced people to do it (negotiating regulatory frameworks is pretty much its own profession).
Country of lawers vs country of engineers
China mostly builds them on the coast to use sea water cooling.
The desert one you refer to is an experimental prototype I think:
https://en.wikipedia.org/wiki/TMSR-LF1
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Don't solar panels have the same problem with heat?
Solar panels decrease in efficiency when hot, but it's not like a complete shutdown.
When your solar panels are hot is noon in the summertime which is when you have way more solar power than you need anyway. Most grids that have substantial solar power are getting saturated with solar power at that time and running everything else at minimum capacity.
They are busy hitting downvote on comments on HN!
You can totally retrofit existing nuclear power plants for closed loop cooling. I'm not sure what the cost would be, though, but it might be worth doing.
I've read that in the case of Paks a retrofit doesn't make sense because the entire thing is so old and needs to be rebuilt anyway.
However, hopefully, they change the plans for (stalled project) Paks 2, because that would've used the same cooling system as the first one.
Is it economically viable to run though? Natural draft towers or direct body of water cooling is used almost universally since it doesn't take any extra power. A large chunk of the powerplant's output would be running heat pump compressors to stop itself from exploding.
Fully closed loop is probably not viable. But I suspect that's not the extreme GP might have meant.
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
How do these things, whose sole purpose is to turn heat into electricity, end up with so much extra heat that it takes more energy than they produce to disperse it? Can't the excess heat in a closed loop system be captured and used to power the cooling? Sorry, maybe this is a stupid question.
Thermodynamics, specifically the Carnot Cycle.
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.
<https://en.wikipedia.org/wiki/Carnot_cycle>
Wouldn’t a Carnot engine with 33% efficiency produce 2 J of heat per 1 J of mechanical work? With 40% efficiency 1.5 J of heat? Efficiency of the generator should be better than 90 % so I think the 3x estimate is a bit off.
The heat doesn't disappear. Useful work is heat, it's just that some of it is intercepted before final dissipation.
If you look at real-world numbers, you're generally going to see 3x the thermal output as electrical output from any thermal energy plant. Two-thirds of that thermal output is wasted, and you'd see your 2x figure there. But the useful electrical output eventually ends up as heat as well, whether in direct thermal applications, from mechanical applications, lighting, refrigeration, audio equipment, or electronics.
The (admittedly theoretical) numbers in this example show that:
<https://energyeducation.ca/encyclopedia/Megawatts_thermal>
Incidentally: this all-but-inevitably leads to an online hand-wringing about the inefficiency of energy systems when an energy flow chart (Sankey diagram) is released, showing a 2:1 "rejected energy" ratio. It turns out that that's not a measured quantity but a modeled quantity, if you read the fine print. The 2/3 loss is just physics, thermdynamics and Carnot as noted previously.
See for example the LLNL (Lawrence Livermore National Labs) energy flow chart diagrams, here for 2023: <https://flowcharts.llnl.gov/sites/flowcharts/files/2024-12/e...>
Some of those qualifications are more legible in the fine print of the PDF: <https://flowcharts.llnl.gov/sites/flowcharts/files/2024-10/e...> (PDF).
Well we are still discussing cooling of power plants. The part of the energy that goes into the grid cannot be used to heat the river. It turns into heat somewhere else.
Yes, that's right.
The heat is spread out to a much larger volume.
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.
okay but to maybe beat a dead horse, if you have these enormous cooling towers spewing out steam, is the steam coming out the top of those just not economically viable to use to run smaller generators or something?
There are plants with multiple stages of turbines. You really do need high pressure, high temperature steam to make appreciable energy though. What comes off the top of a cooling tower will keep you warm, but it's had 99% of its energy already extracted.
The laws of thermodynamics don't allow it. Energy usually comes with entropy attached, which can't be destroyed and has to be dumped somewhere. At a colder temperature you need less energy to raise the entropy, which allows for energy and entropy to be split into a cold part (containing most of the entropy and some energy) and a hot part (containing low entropy) at specific ratios. Electricity is low-entropy energy, which is why it's so useful.
"Heat" is really entropy gain, and so in order to do useful work you have to increase the entropy of the system to higher and higher quantities. If you want to move entropy from one closed system to another(to cool one system down) then you must emplace even more entropy in the one system than you removed from the other because you must spend entropy(generate heat) in order to force a change in the state of the other system. It's a fundamental law of physics. You cannot reduce the entropy of the universe by any means.
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.
5. scrap 1..4 and build a gas cooled reactor instead.
https://en.wikipedia.org/wiki/HTR-PM
First of all you can't retrofit every npp with that, it's a lie. And eve; if you could, you are correct, it's financially not viable. Renewable energy is always the cheaper option by far.
I believe there was also a planned much cheaper retrofit to use pumps to increase force to necessary levels but it was scrapped.
We need a aponge country for these summers, something that can hold onto water.
Related: https://news.ycombinator.com/item?id=49107044
I find it interesting the discussion here is entirely about water temperature whereas the shutdown is entirely about NPSH.
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.
NPSH = Net Positive Suction Head
> 4,700 cubic metres per second in July, whereas on Wednesday it was down to less than a third of that, at 1,600cm per second.
Did a double take at measuring water flow in cm per second. At least it isn’t in busses or Eiffel or something.
Seems reasonable to me, same metrics used in Pooh Sticks.
I ask once again: why is everyone so convinced that nuclear is the one technology that somehow doesn't get cheaper and better with advancing tech and scale? And don't tell me learning curves are proven to not apply. The preconditions for learning curves are arguably only now being met in China.
Go and invent an awesome nuclear plant then.
So nuclear isn't the solution after all.
Nuclear without greed is fine.
Its only where shortcuts have been taken with cooling that there will be issues.
What do you consider adequate cooling? Remember that for every GW of electricity you need to remove 2-3 GW of heat. That's a lot of heat. Strapping a giant PC radiator fan to the plant won't cut it.
That seems like a huge disadvantage for nuclear power if you need to guarantee strict ideological commitment to ignore cost-competitiveness not just now but into the future. Renewables and batteries are not only cheaper now but have far less scope for major failures based on some MBA cutting corners in a decade.
You think big battery plants can't have issues with cost cutting?
So, everywhere, in a Capitalistic society
So basically no.
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"The Danube runs 2,857km (1,775 miles) through 19 countries."
BBC can't even check Wikipedia.
A nuclear plant being forced offline by low river levels is a striking reminder that even low-carbon energy depends on climate-resilient infrastructure. How many plants across Europe face the same cooling-water risk?
If only there was a power source that would excel during sunny and warm days, huh
Then we could stop the nuclear plants when needed for cooling and maintenance
> we could stop the nuclear plants when needed for cooling
Well that's exactly what they did thanks to solar power provided by the rest of the grid, so your snark seems rather unwarranted.
Hungary actually has a ton of solar, video from today: https://www.youtube.com/watch?v=HqpTN5PZLow
The problem is we don't have enough storage to use it after dark.
Desertification is next.
It's now.
Thorium Reactors are the future, much more controllable and "fails safe-r"
they also can "burn" nuclear waste (spent fuel from water reactors)
* https://www.youtube.com/watch?v=ElulEJruhRQ
This is what nuclear power enthusists like to ignore when they talk about nuclear power being a solution to energy and climate change.
Worth mentioning we also had to shut down the largest block in our largest gas power plant on the exact same day due to an unrelated error.
https://www.dert.hu/hu/sajtoszoba/0/141 (in Hungarian, couldn't find an English source)
Is that a fact or are you just trying to spark a debate?
Seems like a fact to me?
They also constantly criticise Germany and its nuclear power plant closures, linking almost every negative news story about the country to this issue. It seems they’re completely unaware of the potential consequences of operating a nuclear power plant.
A lot of energy crisis in Germany is due to the closure of their power plants. Just like any other infrastructure, nuclear power plants needs to be modernised over the time and Hungary didn’t do that. It’s not the fault of nuclear technology, but lack of management in Hungary’s case
Every power source has trade offs, bud. They call solar renewable, but in fact panels have a shelf life, and take valuable finite resources and energy to manufacture. This is what climate change activists like to ignore /s
Glad you added the /s because solar panels only wear out over hundreds of years.