Is it safe considering the 1000 square miles of Ukraine that Chernobyl made uninhabitable? How safe are they against terrorist attacks, an attack by a rogue state or in a conventional war?
Actually, if you are in a war or you are a terrorist, there are much more high value targets than a structure with 1.3m thick re-enforced concrete plus 1cm thick steel dome.
The reason is that ever since Chernobyl there has been an active debate in Germany pro/contra nuclear (where in some parts there are still consumption limits on certain types of wild mushrooms and game due to contamination with caesium - 30 years later, 1000+ km away!). And the core argument pro was the same it is today: We learned from Chernobyl, nuclear reactors are way safer, Chernobyl will never happen again.
But if you followed Fukushima closely while it happened, the fact that Fukushima wasn't Chernobyl was sheer luck - had the wind blown southwards towards Tokyo (and not eastwards out to the sea like it did) Fukushima would have been worse.
I'm in no way saying that we have not advanced massively in science and technology - in fact, we have - I'm saying there are tricky biases at play here that make it very difficult to estimate whether we have learned enough.
Like, this is a reasonable question to ask, but it has been asked and analyzed a lot and the practical answer to it is overwhelmingly against fossil fuels, it's not even close. Coal causes far more cancer than radioactive disasters, but we simply aren't (yet?) holding them accountable for this damage.