It’s tough to find definitive information, in part because so many of the claims here lack specificity, but after looking around for information about the incident it looks like the crew of the Reagan, for the most part, were pretty safe and not dangerously contaminated. On the other hand, personnel *based* in Japan apparently had a different experience and their contamination concerns were not taken seriously. At Yokosuka, particularly. And from what I have been able to those suing are mostly personnel who were based in Japan and mostly in Yokosuka. They apparently did suffer dangerous exposure.
Found this.
https://commons.wikimedia.org/wiki/Category:Radiation_decontamination_of_the_USS_Ronald_Reagan
Went to a lot of effort if the threat was small. Not being critical just observing.