Nuclear waste leak in Wash. "scandalous," expert says

(CBS News) The Hanford Nuclear Reservation in Washington State is called the most contaminated nuclear site in the country. For decades, the federal government has been struggling to clean it up. But now we're learning of new underground leaks of radioactive waste.

And time is the enemy.

The bomb that brought an end to World War II was built with plutonium that was produced at the Hanford Nuclear Reservation in Southeastern Washington State.

In the years that followed, Hanford has become the nation's nuclear dumping ground, a final resting place for 56 million gallons of radioactive sludge, encased in 177 underground storage tanks.

Tom Carpenter, executive director of the environmental organization Hanford Challenge said, "A third of these tanks have failed already. One third! They've leaked a million gallons, there's more to come."

Just last week, Washington's governor confirmed six of those tanks are actively leaking again. Gov. Jay Inslee said, "Washington State has a zero-tolerance policy on radioactive leaks."

But the federal government has already spent billions of dollars and decades attempting to clean up the site.

CBS News' cameras were not allowed on the property, but did capture an above-ground replica of the tanks that are leaking. They were designed with a single layer of steel for maximum life span of 20 years, but the first tanks were built back in the 1940s.

Carpenter said, "They lost their integrity, essentially, their engineered design life, right around the time that we sent a man to the moon in the 1960s."

And while Inslee says that the current leaks pose no immediate risk to the public, the cleanup at Hanford goes on. It's estimated it will take at least 40 years at a cost of more than $100 billion.

Watch Carter Evans' full report in the video above.

The problem is "scandalous," according to CBS News contributor Michio Kaku, a physics professor at the City University of New York.

Kaku continued, "At the time of sequester, taxpayers spend $2 billion per year just maintaining the cleanup operation. Then it was revealed that hundreds of gallons of high-level toxic waste have been leaking over the last several years right into the ground. Eventually into the groundwater and maybe the Columbia River."

Radioactive waste is a "witch's brew of chemicals," Kaku said, explaining it contains the most dangerous chemicals known to science like plutonium, enriched uranium, nitric acid and solvents. "We have 56 million gallons worth of this toxic stuff," he said. "To get this into perspective, to get your head around this, imagine 80 Olympic-sized swimming pools containing the most toxic substance known to science of which two Olympic-size swimming pools have leaked right into the ground and eventually into the water table and, perhaps, even into people's drinking water."

For Kaku's full "CTM" appearance, watch his full interview in the video below.

Kaku said we need to consider the problem as an emergency. "The government promised 10 years ago that it's under control. Now we realize it's not," he said. "They have to take the waste, put it into new vats that are double, triple lined. They have to drill to assess how far the waste is. And it's a ticking time bomb. In 15, 50 years -- we don't know when -- it's going to hit the ground table. When it hits the ground table, it will go right into the Columbia River, and remember, that's one of the major rivers in the entire Pacific Northwest."

"Very scary," Kaku said. "It the legacy of the Cold War -- Russia and the United States. We both have black eyes when it comes to handling nuclear waste."