At the same time EU had no proper army to defend itself because dependance on US or a way to supply said army.
Europe does have uranium resources, for instance the Salamanca/Retortillo project, but the constraint is permitting, environmental acceptance, waste handling, and political legitimacy rather than geology. So the honest claim is not "nuclear makes Europe autarkic". It is "nuclear gives Europe a more diversifiable and stockpilable dependency than gas, provided Europe also invests in mining, conversion, enrichment, and fuel fabrication capacity".
Only Slovakia and Hungary. They will need to find a way. (Finland planned it but cancelled after Russia invaded Ukraine.)
There is zero chance that new nuclear plants in Europe will use any Russian tech or fuel.
Kazakhstan is by far the largest uranium producer in the world and has a leg in Europe, west of the Ural river. The important thing is that there are more stable partners worldwide for uranium than Russia is for oil and gas.
There are deposits in Europe, the respective countries decided not to exploit them [0]. This could change depending on external pressures.
[0] https://www.sciencedirect.com/science/article/pii/S2211467X2...
The dictator now makes more money, so we just lost our cheap gas source, and we buy more expensive oil from others.