That's true. They used same words before... But after Chernobyl and Fukushima... How they can expect we believe them?
Opponents: Don't build new reactors.
<older designs have problems that still kill fewer people than any other alternative>
Opponents: See? See? You said...
Proponents: ...that newer designs are safer than older ones and even older ones are safer than alternatives. Which remains true.
...
Politics occurs here. When you ask whether something is safe, in practice what you're asking is if it's safe relative to alternatives. So solar is safe because it's safer than coal, and nuclear is safe because it's safer than solar.
But there is also an absolutist definition of safe which requires an inhuman perfection that no real technology could ever meet. Not solar, not nuclear, not biofuels, it's just an unattainable standard.
So you ask if something is safe, people say yes (meaning it's safe relative to alternatives), then you apply the impossible standard and claim that they're lying.
If you want to stop nuclear over safety with any credibility you would also have to be willing to stop everything with a worse safety record. But that's every known alternative whatsoever.
Not the case. The worst case with nuclear is much worse than with solar, even if the possibility is unlikely. We expect insanely high standards for airplanes and the standards should be even higher for nuclear plants. We should account for the possibility that civilization collapses or an unexpected event reduces a plant to rubble. In both of those cases solar is fine but nuclear is not.
It isn't. The worst case with solar is that they're manufactured with lead, cadmium and other toxic substances that pollute the environment if they're improperly manufactured or disposed of. If you abandon a solar farm, the panels get damaged by weather and then the heavy metals leech into the ground. The environmental impact of that for a solar farm with power output equal to a nuclear reactor would be as bad or worse than a nuclear meltdown.
On top of that, the real worst case for solar is that the storage technology it needs to replace carbon energy sources never becomes economical, and then without having built nuclear today, we get a level of climate change that causes human extinction.
Something bad (earthquake, tsunami, etc) could still happen that causes a plant shutdown. But there's no pressure vessel (other than regular steam on the generating side) to worry about breaching. And unlike current generation reactors, where even a full scram of control rods still requires some hours of active cooling to prevent core meltdown, if the liquid-type loses power, the core drains, and that's the end of it in terms of potential radiological release. That doesn't mean it isn't a complex, difficult system to design and operate. But it's a much, much safer design by its very nature.
( https://chem.tufts.edu/AnswersInScience/RelativityofWrong.ht... , it is an enjoyable essay to read. )
You are correct that flaws and surprises lurk in all human endeavors. But that does not mean that all potential errors are in the same scale or class. We do not know everything, but we know far more than nothing!