Asssuming that the second one is for css purposes (or similar) then it
would be better to move the class out to a surrounding element, the
td, tr or even form for example.
What Colin said - there’s not a single “element” for radio buttons. You didn’t state which Javascript library you’re using, but presumably it has a solution for radio buttons.
Also note that the ability to not have any of them checked is widely supported among browsers but not in keeping with the standard: