The U.S. Supreme Court on June 21 struck down a Washington state workers’ compensation law that was designed to make it easier for workers at the Department of Energy’s Hanford Site to receive compensation benefits. The court, by unanimous decision, found that the law violates the U.S. Supremacy Clause and discriminates against the federal government and its contractors.

Located near Richland, Wash., the Hanford Site produced plutonium for the U.S. weapons program for more than 40 years and is currently undergoing a massive radiological cleanup mission involving around 10,000 workers.