*238 Appellant's decedent, a laboratory analyst at a federally licensed nuclear plant in Oklahoma operated by appellee Kerr-McGee Nuclear Corp. (hereafter appellee), was contaminated by plutonium. Subsequently, after the decedent was killed in an unrelated automobile accident, appellant, as administrator of the decedent's estate, brought a diversity action in Federal District Court based on common-law tort principles under Oklahoma law to recover for the contamination injuries to the decedent's person and property. The jury returned a verdict in appellant's favor, awarding, in addition to actual damages, punitive damages as authorized by Oklahoma law. The Court of Appeals, inter alia, reversed as to the punitive damages award on the ground that such damages were preempted by federal law.