Restarting America's nuclear power industry is frequently suggested as a means of curbing greenhouse gas emissions. But advocates of this back to the future scenario should study Robert Alvarez's recent report showing that the amount of plutonium buried at the Hanford Nuclear Reservation in Washington State is nearly three times what the federal government previously reported. This means that a cleanup to protect future generations will be far more challenging than planners had assumed. And that's before any more nuclear waste is added to the toxic legacy of Hanford's forty years of Plutonium production.