Enough nuclear fuel could be easily shipped to Germany, unlike the necessary natural gas.
Roughly 1/3 is used for heating, 1/3 is used by the industry. None of those can be replaced by electricity in the short run, nuclear or otherwise. Probably only part of that could even replaced by electricity in the long run. Only 14% is used for power generation, but this part is for the "we need more power right now for current demand, and not more power in 10 hours after we've started the nuclear plant".
> Replacing 12% of the electricity supply with something other than Russian gas, along with the other measures being taken, is enough to eliminate 100% of Russian gas imports.
Completely wrong, sorry...
[1] https://de.statista.com/statistik/daten/studie/37985/umfrage...
They are usually not used that way because their base load is needed.
Also, if you do not know that, you might reflect about what other facts relevant to forming an educated opinion on the topic you are missing.