A look back at a nuclear facility with fresh leaks

Most people think "Chernobyl" when it comes to nuclear disaster, but one of the most contaminated nuclear sites in the world is in Washington State

Most people think "Chernobyl" when it comes to nuclear disaster sites. But outside of Russia, the most contaminated nuclear site in the world is right here on the beautiful Columbia River in the Pacific Northwest. At Hanford Nuclear Facility in Washington State, 56 million gallons of radioactive waste sit in underground storage tanks. Those tanks have already leaked more than one million gallons of a toxic brew of plutonium, enriched uranium, nitric acid, and solvents into the ground.

But that isn't news to anyone living downriver from Hanford. The facility started leaking decades ago, and the government has already poured billions of dollars into trying to clean up the liquid waste left over from the production of nuclear bombs at Hanford, including the bomb that was dropped on city of Nagasaki during World War II.

Last week, officials admitted that at least six Hanford tanks are currently leaking. "The government promised 10 years ago that it's under control. Now we realize it's not," CUNY physics professor Michio Kaku told CBS News this week.

But news of the latest leaks isn't surprising to the 60 Minutes team that reported in 2006 on Hanford's problems, including the many construction errors made at the facility. Watch Lesley Stahl's report in the above video player to learn about the mind-boggling mistakes made at the site, like the decision to build a pretreatment facility for radioactive waste that wasn't designed to withstand an earthquake.

And if you're wondering about an updated cleanup timeline of what amounts to 80 Olympic-sized swimming pools of the toxic brew, it's estimated that it will take at least 40 years at a cost of more than $100 billion.