Flamanville 3 is a new reactor, which was first connected to the grid late December 2024. Its standby consumption seems to be roughly the same as the other reactors.

I'm not an expert but to me it looks like they are still in some kind of testing/verification/certification phase? According to its operator's website[0] they ran into some minor technical issues during ramp-up, which of course have to be fixed as well.

The alternative is going into full production before testing has been finished, but that's how we got Chernobyl. I'd rather have it operate at an energy loss for a few months so they can carefully work out all the teething problems than have it irradiate a decent bunch of France and England.

[0]: https://www.edf.fr/la-centrale-nucleaire-de-flamanville-3-ep...