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Comment by lnz_me | Hacker News Reader

i love the "but nuclear" crowd as they seem to gloss over that a nuke is a steam engine and needs water. water we don't have anymore. if you follow the news in europe you'll see every summer that country X (normally france) has to drastically reduce or switch off their nukes because no water.

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I live in France, and the nuclear power is working perfectly fine. France has about half the carbon emissions of Germany per capita entirely because of German neuroses about nuclear power. While occasionally, they have to turn off one or two reactors so the fish in a given river aren't too hot, it's hardly causing rolling blackouts or energy shortages.

Renewables also occasionally don't work as well, whether during the night or when the wind isn't blowing (before you retort with oh, but what about batteries, well, those would equally apply to reactors, in which case your original point is irrelevant).

Romania blasts rock to divert water from drought-hit Danube to nuclear reactor - https://news.ycombinator.com/item?id=49158035 - August 2026 (0 comments)

What's happening in Hungary's power grid? - https://news.ycombinator.com/item?id=49154001 - August 2026 (0 comments)

Hungary to shut down sole nuclear plant as Danube falls to record low - https://news.ycombinator.com/item?id=49145531 - August 2026 [dupe]

EU considers emergncy meeting as nuclear shutdown leaves HU facing energy crisis - https://news.ycombinator.com/item?id=49131244 - August 2026 (1 comment)

How Hungary became the best at solar [video] - https://news.ycombinator.com/item?id=49125682 - July 2026 (1 comment)

Danube's record low levels force shutdown of Hungary's only nuclear plant - https://news.ycombinator.com/item?id=49120120 - July 2026 (231 comments)

France powers down several nuclear reactors due to extreme heat - https://news.ycombinator.com/item?id=48899232 - July 2026 (19 comments)

Europe's extreme heat is shutting down power plants - https://news.ycombinator.com/item?id=48697170 - June 2026 (2 comments)

Commercial nuclear generation is incompatible with a rapidly warming planet due to cooling demands.

Europe's summer heat has broken the Bell curve - https://news.ycombinator.com/item?id=49158483 - August 2026

Bloomberg: Europe’s Key Rivers Are Drying Up as Extreme Heat Impact Widens - https://www.bloomberg.com/news/articles/2026-08-02/europe-s-... | https://archive.today/tVpQJ - August 2nd, 2026

> Europe’s biggest rivers, including the Rhine and Danube, are drying up after a series of heat waves, disrupting the transport of goods and boosting freight costs. Soaring temperatures are curbing power generation at riverside reactors, pushing up energy prices and straining Eastern European economies. The river disruptions are becoming a test of how quickly the region can adapt infrastructure to a climate where extreme low water is likely to be increasingly common.

Bloomberg: Europe’s Endless Heat Waves Imperil Once Reliable Power Sources - https://www.bloomberg.com/news/articles/2026-08-01/europe-s-... | https://archive.today/EvSSS - August 1st, 2026

> A series of heat waves has weakened some of Europe’s most historically reliable sources of electricity, forcing the continent to lean more heavily on imported fossil fuels and variable renewable energy. France’s river-cooled nuclear plants have suffered a record amount of heat-related outages this summer, and hydroelectric plants in the Alps and Nordic region have been hobbled by hot, dry weather. The heat-related strains coincide with a surge in natural gas and coal prices, and the disruptions are poised to push power prices even higher, leaving Europeans facing steeper electricity bills.

> France powers down several nuclear reactors due to extreme heat - https://news.ycombinator.com/item?id=48899232 - July 2026 (19 comments)

There's no technical reason why the reactors in question could not have kept running:

> "Due to the weather conditions and to comply with regulations on [cooling water] discharges, and thus to protect the environment," reactors at the Golfech, Bugey and Chooz plants, located on the banks of the Garonne, Rhône and Meuse rivers respectively, have been shut down, the EDF energy group told Agence France-Presse.

> The measure is an environmental protection requirement to avoid discharging too much hot water into rivers already warming from the heatwave. Power plants critical to the country's electricity production use river water to cool their reactors, which heats the water that is then released back into the river.

> The Economy Ministry on Saturday issued an exemption to the temperature limits for the heating of the Rhône around the Bugey plant "to ensure the security of the power grid," valid until July 20.

There's no physics reason of course, but not using the natural river source for cooling like this further hurts the economics of nuclear power, which is already it's primary weakness.

Similarly, all industrial processes of heat rejection, including data centers, could use closed cycle cooling, but they don't, because it's more expensive to install and operate.

> the economics of nuclear power, which is already it's primary weakness.

That affects ~0.5% of the yearly production in France, it's not a "primary weakness", it's the opposite, it's so low of a problem that the state simply doesn't care enough to fix it.

They are saying economics is the primary weakness i.e. nuclear costs more than renewables even if you don't have fancy cooling methods that would increase the cost further.

For renewables (solar, wind) to work reliably you have to provide on-demand backup, invest in energy storage systems and increase investments in electric as renewables are often far away from consumers. (German offshore wind in north, major industrial consumers in south). So direct comparison of isolated costs of renewables and nuclear is misleading. You have compare the whole system.

People who did this found renewables to be cost effective.

"Germany has one of the most ambitious energy transition policies dubbed ‘Die Energiewende’ to replace nuclear- and fossil power with renewables such as wind-, solar- and biopower. The climate gas emissions are reduced by 25% in the study period of 2002 through 2022. By triangulating available information sources, the total nominal expenditures are estimated at EUR 387 bn, and the associated subsidies are some EUR 310 bn giving a total nominal expenditures of EUR 696 bn. Alternatively, Germany could have kept the existing nuclear power in 2002 and possibly invest in new nuclear capacity. The analysis of these two alternatives shows that Germany could have reached its climate gas emission target by achieving a 73% cut in emissions on top of the achievements in 2022 and simultaneously cut the spending in half compared to Energiewende. Thus, Germany should have adopted an energy policy based on keeping and expanding nuclear power."

https://www.tandfonline.com/doi/full/10.1080/14786451.2024.2...

Germany invested in renewables already at a time when they were very expensive. This created an economy of scale that brought prices down to everybody. Nuclear was never economical anywhere, so no, Germany should not have expanded nuclear. I think it could have kept them running a bit longer, but those decisions were made a long time ago and changing them also has a cost.

Isn't this the guy that double counted everything? Because he counted when something got bought and then counted the subsidy used to buy and added then together?

Double-counting was criticism from Fraunhofer ISI. Jan Emblemsvåg has responded to the criticism with follow on article:

https://www.tandfonline.com/doi/full/10.1080/14786451.2026.2...

Doing a quick search for Emblemsvåg, this seems fairly relevant:

> […] He has researched and published significantly in Life-Cycle Analyses, Life-Cycle Costing, energy, risk, Lean and other areas. […]

* https://www.ntnu.edu/employees/jan.emblemsvag

> Everyone jokes about the 20/20 hindsight of cost management. In Life-Cycle Costing, Jan Emblemsvag proposes to do something about it. Here's a new approach to life cycle costing that brings activity-based costing, risk, and uncertainty into the forefront. You'll focus on future costs and learn how you can perform any type of cost management activity better than before by introducing uncertainty into models and exploiting them to the max.

* https://www.wiley.com/en-us/shop/general-introductory-accoun...

Well no it isn't, this problem is so small that it's not even worth installing any additional cooling method. It's also the lowest consumption period of the year, making the problem even more irrelevant as some plants are already offline for maintainance anyways.

And since the poster didn't knew that, I'm not sure the cost analysis holds up.

>commercial nuclear generation is incompatible with a rapidly warming planet due to cooling demands

Well it's good that Germans chose coal over nuclear!

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