The French can only do that because they have so many reactors. If you ramp down a reactor, it poisons it's own fuel with radioisotopes and you can't safely ramp it back up - at least not quickly. You need to wait for the neutron poison to decay naturally, which takes days or even weeks, depending on how much you turned down the reactor.

The reason the French can get away with it is because they have to. If you have this much nuclear on your grid, you can't get around it, the reactors need to follow demand. The good news is that because they have so many reactors, they can have them take turns poisoning their fuel and still have enough time to slowly come back up again. So each night a different reactor ramps down and gets poisoned.

Also, French reactors can take the financial hit of decreasing output much better than American reactors. Nuclear has so small margins that if you tell the investors of a new nuclear plant in the US that their reactor will be required to ramp down a couple of times per month, the entire project turns into a huge financial loss just like that. They need to run at 100% all year, or lose billions.

> So each night a different reactor ramps down and gets poisoned.

They do it intra-day. You can currently follow that through their monitoring [^1]

> Nuclear has so small margins that if you tell the investors of a new nuclear plant in the US that their reactor will be required to ramp down a couple of times per month, the entire project turns into a huge financial loss just like tha

Nuclear reactors tends to be hugely profitable considering their lifetime (80y in USA) but requires an enormous CAPEX.

Like most infrastructure, any attempt to try to fund them entirely privately with investor seeking a 9% quick ROI is doomed to fail.

Hinkley Point is a very good example of that. It is estimated that the price per MWH would be more than halved if the project would have a funding by public bond instead of the current private investor deathtrap.

[^1]: https://energygraph.info/d/gr_6-QW4z/unit-availability?orgId...

That's only "economical" because the French taxpayers subsidize EDF with billions of euros both in direct subsidies [1] and in the form of price caps [2].

[1] https://www.theguardian.com/business/2022/feb/18/french-gove...

[2] https://www.bloomberg.com/news/articles/2023-11-14/france-an...

That is deeply incorrect.

EDF as hugely profitable and brought back billions to its main stock holder (the French state) for multiple decades.

The recent debt crisis has mainly two causes:

- The state has used EDF to shield consumers against the 2022-2023 energy price increases. EDF has taken the losses directly for the state.

- The results of terrible energy policies the last decades (attempt to reduce nuclear at 50% and mainly the infamous ARENH).

What happened is pretty typical of when you have a state is directly managing a private actor: Incompetent politicians swiping their foots on the company to satisfy their own demagogy.