Hungary nuclear plant cuts output because of warm Danube waters

[taylodl]

Nuclear power plants and coal-fired power plants work off the same principle:

Use the heat to boil water to create steam, run the stream through a steam turbine, and condense the steam back to water. This water is continually recycled throughout the system.

The river water is used to condense the steam back to water and then the water is discharged back to the river - warmer than it came in. If the water coming in from the river is too warm then the condensation rate increases until you get to the point it's out of spec. You can't condense the water fast enough. You need to reduce the plant's output, i.e. reduce the heat.

On the other end the discharge water is always warmer than the intake water. As the intake water warms then the discharge water will also warm - all other things being equal. You'll get to the point the discharge water will raise the water temperature to the point where aquatic life is negatively impacted. There are also laws mandating the maximum temperature for the discharge water.

So, you have to reduce output. That's just how these plants work.

That's the nice thing about natural gas plants - the gas turbines are essentially jet engines - they're fueled directly, no steam or cooling required.

This is something rarely talked about in the solar and wind discussion. People love to point out that the wind and the sun provide intermittent power, while ignoring more and more traditional power plants are curtailing output as water temperatures rise or water levels lower (water intake pipes would be exposed).

[unglaublich]

We don't talk about it, because we want to get _away_ from igniting huge amounts of underground carbon-based material and putting it straight in the atmosphere. We want to move to methods of power generation that do _not_ significantly upset the delicate balance of a livable planet.

Continuing adding more carbon to the atmosphere is only worsening the situation.

[jeffbee]

Large gas power plants are combined cycle steam plants. Only the smallest ones are simple cycle as you describe. Large gas power stations are as complicated as any other thermal power station.

[stephen_g]

We have this problem with coal plants in Australia - in Summer often there are unplanned coal unit outages on hot days (due to this kind of thing, among other reliability issues with the aging plants - I don’t think ours use river water but this kind of cooling issue), and it’s always right when the grid is stressed with all the air conditioners running…

And of course the rightwing media starts the chorus of ‘those bloody renewables’ causing problems, even when solar especially is actually helping us ride through some of the coal unreliability!

[acidburnNSA]

You can do air cooling with nuclear plants as well, for locations that don't want to or can't use a water supply. Costs more, but totally doable.

https://www.youtube.com/watch?v=T9S1P54n1FA

[manwithaplan]

> the temperature of the Danube, whose water is used to cool the plant, reached 29.72 degrees Celsius

[Filligree]

Still works for cooling, right?

It's not that there's any technical issues; it's that there's ecological issues. Though there's going to be much larger ecological issues if we have to replace it with coal.

[tekla]

"Nuclear plant does what it is designed to do"

[andsoitis]

The news here, and thus the interesting and probably unexpected thing to note, is that if we depend on natural sources for water to cool nuclear plants and due to climate change the temperature of waters rise, we need to adjust where we build plants and/or spend extra energy to cool down the water to in turn cool down the plants.

[sp332]

Climate change starts hurting one of our best chances of avoiding climate change.

[domenkozar]

Note that warm waters is a typical strawman argument against nuclear power.

These are rare anomalies and there's dry-cooling of nuclear power plants (although it's less efficient and costs more).

[epistasis]

These are as rare as the week long events of low wind. Meaning that we must plan for nuclear curtailment just as we must plan for unusual wind weather: with backup generation and with storage.

Trying to brush aside legitimate engineering challenges as "not real" seems far too common among nuclear advocates. Which is my guess that their construction projects fail so often; the engineering and logistics and construction are significant challenges that are not taken seriously enough.

If the nuclear industry took engineering and problem solving as seriously as those in solar and wind, we would probably have a lot more nuclear around, a lot more successful construction projects, and nuclear that was cheap enough to build.

[dragonwriter]

> Note that warm waters is a typical strawman argument against nuclear power.

A strawman is a false opposition argument set up to argue against, so, no, its not. I am not even sure what you are trying to say, but “strawman” isn’t it.

Also, most proposed new reactors a aren’t dry-cooled and the arguments, which include cost, for nuclear don’t assume that higher cost option.

[unglaublich]

Plus, it's a design parameter in a performance/cost trade-off.

It's _designed_ to not work at full power at this heat, because that was thought to be the ideal trade-off.

Maybe it still is, maybe they underestimated the occurrence of high water temperature incidents, but in any case it's a consciously designed safe state.

[DarkNova6]

Plus, most reactors were built in the 70s/80s when waterflow of rivers was more plentiful and less warm on average. Ironically, nuclear contributed to none of that.

[spywaregorilla]

Rare anomalies currently. Will they continue to be rare anomalies going forward? Also, high heat moments are the times when you likely need more power than ever...

[akamaka]

Creating heat to turn into electricity is an outdated 19th century idea at this point.

Now that we’ve mastered the technology to turn ambient energy directly into electricity, traditional nuclear reactors are an overly complex technological dead end.

[cygx]

These are rare anomalies

Note that partial shutdowns due to excessive heat happen regularly in France, e.g. in 2018, 2019 and 2022. The problem's been around for a while, see e.g. this article [1] from 2009 that also mentions the heatwave of 2003, where regulators had to grant special exemptions to allow discharging 30°C water into waterways, well past the 24°C limit.

[1] https://web.archive.org/web/20110612153407/http://business.t...

[croes]

To what extent is it a strawman when it comes to nuclear power generation?

These rare anomalies could happen more often because of climate change and the existence of dry-cooling power plants doesn't help if yout already existing isn't

[throwbadubadu]

Never heard of dry-cooling nuclear reactors, how much less efficient, also less safe? Does a prototype even exist? Some reference please.

Will we call the rare anomalies rare until it they are the norm? And then?

[senectus1]

nuclear power plants are not environmentally friendly. sure they're carbon friendly and "green" in other ways, but the mining of uranium is horrendously dirty, the long term storage of the waste is dirty as hell and this waterways heating issue is just another problem.

green renewable should be our goals, we're bathed in power every day it just needs to be bottled. nuclear plants have their place, but its few and far between and i would argue less than desirable in general.

[titzer]

A typical large scale nuclear plant produces 3 cubic meters of waste fuel which is (in the US at least) stored onsite in cooling pools. It is not "dirty as hell".

> green renewable should be our goals, we're bathed in power every day it just needs to be bottled.

There is a lot to unpack in this vague statement, but generally speaking, utility-scale power generation from nuclear has the lowest ecological footprint, not just in land area, but all-told. A solar farm is a big, complex, thing with a huge footprint.

[Moldoteck]

the long term storage of the waste is dirty as hell - It's not! France manages to recycle a lot of it's fuel(not sure if all), 90% gets back to reactor, 10% is transformed in solid state via vitrification for long term storage, where only first ~300 yrs are really dangerous bc of the decay speed of these 10% Why others don't do this? Fk knows, fossils lobby I guess+ some other 'reasons' that are not that important. There are similar reprocessing plants in Japan and (maybe) China and one more county

[pif]

> green renewable should be our goals

Comfortable life for everyone is my goal.

> we're bathed in power every day it just needs to be bottled

That word "just" proves that you don't know what you are talking about.

[cowl]

> but the mining of uranium is horrendously dirty,

if you go down enough the chain of anything you find something that is not so friendly. And anyway that is a call to review Uranium mining practices not a condamnation of nuclear tech. In sum nuclear power plants are friendlier that everything we have right now.

[theandrewbailey]

> but the mining of uranium is horrendously dirty, the long term storage of the waste is dirty as hell and this waterways heating issue is just another problem.

The production of renewable infrastructure, and mining for the materials required to produce them is also horrendously dirty.

[troupo]

> the long term storage of the waste is dirty as hell

90% of waste can be safely stored on-site, and is short-lived.

The remaining waste is ridiculously minuscule, and can probably fit in a few shipping containers. The main reason it's expensive to store is politics.

> it just needs to be bottled

"just".

[no_wizard]

what if you just pooled the water until it cooled down naturally under shade before discharging back into the Danube?

[hansthehorse]

Turkey Point plant in SE Florida uses miles and miles of man made switchback canals to cool the discharge before it returns to the plant.

[freeone3000]

The water, coming from uphill, is already cooler than it would be if it sat still at the current altitude. Streams and springs average the temperature out over months, not simply a few hours.

[fnord77]

so is there no way to convert radiation to electricity directly without heating large amounts of water?

some Seebeck thing?

[boomboomsubban]

For other Americans, 29 C is 85 F.

[abruzzi]

and Burmese and Liberian.