[logicallee]

Like the sibling commenter, I can't parse your sentence and intention except as "we've certainly shown they're not commonly problematic" which is quite a weak statement.

Is your sentence a positive sentence (do you mean we've certainly shown they're problematic essentially never) or is your sentence negative (we've certainly shown they're problematic definitely sometimes - which is unacceptable)?

I tried to read your attitude but failed.

[Aron]

I was mostly rebuffing the structure of the argument "While in theory we can build safe reactors, practice shows otherwise" which has two different reference classes for reactors (modern safer ones, and less safe fukushima ones).

[logicallee]

Oh, okay! It was confusing because it sounds like "they're rarely problematic" which is not your meaning. Thanks for the clarification!