The Tenth Circuit Court of Appeals has vacated a $926 million judgment against former operators of the Rocky Flats Nuclear Weapons Plant near Denver, Colorado, because the trial court gave the jury improper instructions. Cook v. Rockwell Int’l Corp., No. 08-1224 (10th Cir. (09/03/10). This class action was brought by 1,500 plaintiffs who complained their property values were diminished due to plutonium contamination at the weapons plant.

The litigation was a public liability action filed under the Price-Anderson Act—the federal liability law governing nuclear radiation exposure—alleging trespass and nuisance claims arising from the release of plutonium particles onto plaintiffs’ properties. The complaint sought compensatory and punitive damages, as well as interest. The district court entered a final judgment against defendants on June 2, 2008, after the jury found that defendants must pay $726 million in compensatory damages and $200 million in punitive damages. Cook v. Rockwell Int’l Corp., 564 F. Supp. 2d 1189 (D. Colo. 2008). Defendants appealed.

On appeal, plaintiffs argued that the mere presence of radioactive plutonium particles on their property established a nuclear incident within the parameters of the Price-Anderson Act. They argued that plutonium contamination itself was sufficient to establish “damage to property.” The appeals court disagreed saying, “[t]his argument misses the point.” According to the court, “[t]he statute does not indicate that the mere presence of plutonium is per se injurious to property.” To prevail, plaintiffs must show evidence of actual physical damage to the property or loss of use of the property, neither of which the district court required them to show in its jury instructions. Accordingly, the appeals court reversed and remanded for further proceedings.