France is the only country that offers more than 50% nuclear, achieving 75% of electricity from nuclear. It’s given it a long-term headache that will only be resolved in a few more decades as the reactors age out and can’t be refurbished (Bias Check?...Facts or biased opinion?). Thankfully, France exists within a continent-scale grid that can accommodate the inflexibility of the nuclear fleet (Bias Check?...There is nothing inflexible about nuclear power), buying electricity when France can’t easily turn down the plants and selling France electricity when it needs it because it can’t turn the fleet up either [Bias Check too? Probably needed power because renewables fell short and coal production was clouded by smog?] As President Macron of France has said, he used to run the Finance ministry for France and even he has no idea how much they’ve spent on nuclear [Bias Check again? Basis? Source? Sounds like Trump-like BS].
Four smaller countries, Ukraine, Slovakia, Belgium, and Hungary, also produce more than 50% of its electrical needs by nuclear power.
Ontario in Canada is the size of many countries, with a GDP in the top 20 compared to countries globally and more people than half the countries on Earth. It has extended its nuclear generation to about 55% over the past decade, which is preferable to having their coal plants persist, but less effective than buying hydroelectricity from Quebec and building more wind and solar (Bias Check again re wind and solar. Source? Also sounds like BS]. They are extending their debt-ridden nuclear hangover by refurbishing reactors that don’t have a business case and amortizing the existing, long-deferred nuclear debt over even more years to prevent current rate payers from paying the true cost of the nuclear fleet [Fact Check? This is large scale economics to keep the customer's long-term electrician costs down, not the economics associated with windmills and sun-farms, where O&M costs are not accurately included in start-up economics used to justify construction of windmills and sun farms].
The only country which has built a lot of nuclear in the last 20 years is China, and it has both built a lot more wind and solar in the same period in real generation terms [Fact and Bias Checks Required Here! Not comparable in numbers just output] and is slowing its nuclear build out [Falsehood ! In fact, an acceleration of construction is underway (more)].