00000179-65ef-d8e2-a9ff-f5ef8d430000The Hanford Nuclear Reservation in southeast Washington was home to Native Americans and later to settlers. It turned into an top-secret military workhorse during World War II and the Cold War. Now, it’s one of the most pressing and complex environmental cleanup challenges humanity is facing in the world.This remote area in southeast Washington is where the federal government made plutonium for bombs during WWII and the Cold War. It’s now home to some of the most toxic contamination on earth, a witch’s brew of chemicals, radioactive waste and defunct structures. In central Hanford, leaking underground tanks full of radioactive sludge await a permanent solution. Meanwhile, a massive $12 billion waste treatment plant, designed to bind up that tank waste into more stable glass logs, has a troubled history.00000179-65ef-d8e2-a9ff-f5ef8d440000Anna King is public radio's correspondent in Richland, Washington, covering the seemingly endless complexities of the Hanford Nuclear Reservation.