That Wikipedia page explicitly states that the public has never subsidized damage from a nuclear accident. Nuclear energy companies are required to have $450M in private insurance for each reactor. For amounts over that, the Price-Anderson Act requires all nuclear energy companies to pay up to $121M per reactor, for a total of $12B in coverage. The public would potentially cover anything after that $12B, but that has never happened.

If every nuclear reactor in the US simultaneously had an accident requiring the $70M paid out for Three-Mile Island, we'd be around 1.2% of the way to needing Treasury funds. Three-Mile Island's operator was responsible for cleaning it up, and they paid the entire $1B required to do so.