Created to survive a possible atomic conflagration, the nuclear people are syntethic mutants that live in Earth-AD, (now know as Earth-51). They posses an artificial atomic heart which lets them transform their bodies into living metal. Most recently, one of them, Ben Boxer, has been upgraded to OMAC power levels, becoming biOMAC. It is unknown if that is an ability that is only present in Boxer or if all the nuclear people can access OMAC level powers.