> If it's so cheap why us France selling at loss?
It's a long story. Basically EDF (électricité de France) was a monopoly (which is fine because it's nationalised) but Europe asked to break this monopoly (capitalism says monopoly = bad). The problem is that third parties can't really build nuclear power plants or hydroelectric dams to generate their own electricity (because it's hard and expensive, which is why it was nationalised in the first place), so Europe forces EDF to sell electricity to the European market at a fixed price (which is currently lower than the market price) which is then bought by third parties and sold to customers for a profit.
The bottom line is that EDF was built with public money and is now financing private entities at a loss...
Now for the fun part, these competitor don't do anything other than buying low and selling high. EDF still is a monopoly in term of energy production, it's just not allowed to benefit from it. None of these third party benefits are reinjected in the country's energy production system.
> either they're forcing other countries to give up nuclear power
It's an ongoing process, they themselves want to stop nuclear but for now they're very happy about buying electricity from nuclear powered countries.
If you want to read more about it:
https://ec.europa.eu/commission/presscorner/detail/en/IP_10_...
https://www.connexionfrance.com/French-news/EDF-to-sell-more...