Nuclear power has been economically inefficient for a long time.
This is true for many, many economies. Even in places like Japan and South Korea, nuclear energy is more expensive than seaborn LNG.
The reason that nuclear energy has been supported is the "unspoken" externality.
https://en.wikipedia.org/wiki/Nuclear_latency
Having a "peaceful" nuclear plant, means you can throw together a bomb pretty quickly if needed.
Hence countries like Japan/Korea, with active space and rocketry programs as well as a thriving domestic nuclear power industry, have been considered "quasi-nuclear powers" by many. Their "time to slap together an atom bomb," given a large national supply of nuclear physicists is not that long.
Germany, is very supporting of pacifism.
Hence, since the German approach to foreign policy is fundamentally "we don't want nuclear weapons because we really don't want to engage in warfare, because warfare is immoral." They don't want nuclear power.