The US imports uranium from 12 countries and has its own deposits. Plus you can stockpile it. It was probably more to prevent Russia from selling to terrorists than a dependency.
It was the opposite - the lack of a boogey man in ~2011.
They were shut down because they weren't that reliant on it to begin with (the level to which electricity from nuclear power mattered to Germany is routinely exaggerated), because they were horrendously expensive to maintain and fix (nuclear power is always $$$$$$$$$) and because of Fukushima.
Most countries that are build their own nuclear power plants or nuclear power plants in other countries (e.g. Sweden, France, America, Russia) either have expensive nuclear arsenals which they want a nuclear industrial base to help maintain or have a boogeyman that makes them want to be able to ditch the NPT and build a nuke in a hurry. For Sweden that's Russia, for Iran that's America, for Japan that's China.
Poland has just recently gotten interested in building nuclear power stations, after having zero interest for a long time. You can probably guess which boogey man was responsible for that.
Maintenance on aging plants is also very expensive (just ask the French) and German plants were getting long in the tooth.
Decommissioning is also very, very expensive, and disasters like Fukushima are also very very very expensive (that one cost about $1 trillion).
It wasn't some secret plot by Russia. Russia exported most of the uranium they used. Fukushima just made nuclear power more of a headache than it was worth, especially given the cost and pressure from the environmental movement (who had agency, despite what you might believe).
The reliance that the US/Europe had on Russian uranium is, in fact, one reason why it was never sanctioned.
The greens in Germany are mostly captured by America these days - that's why they shifted to becoming massive war hawks.
Poland had a quarter of Germany's per capita GDP in 2010. You're basically saying that German acted like a developing nation in term of it's energy strategy. That's not a positive argument. When you don't have money then you do whatever you can to survive. When you do have money then you need to think about the future. Poland's GDP is now half of Germanys so it's doing just that since it now has the money to do so.
https://www.reuters.com/markets/commodities/russia-restricts...
The U.S. of course is a sovereign nation and can decide for itself how long it trades with countries that it calls "terrorist states".