Nuclear waste U.S. could power the U.S. for 100 years

There is enough energy in the nuclear waste in the United States to power the entire country for 100 years, and doing so could help solve the thorny and politically fraught problem of managing spent nuclear waste.

That’s according to Jess C. Gehin, an associate laboratory director at Idaho National Laboratory, one of the government’s premier energy research labs.

The technology necessary to turn nuclear waste into energy is known as a nuclear fast reactor, and has existed for decades. It was proven out by a United States government research lab pilot plant that operated from the 1960s through the 1990s.

For political and economic reasons, the technology has never been developed at commercial scale. Today, there’s an increased urgency to address climate change by decarbonizing out energy grids, and nuclear power has become part of the clean energy zeitgeist. As a result, nuclear fast reactors are once again getting a serious look.

“It feels like it’s real — or realer — than it has ever has been to me,” said Brett Rampal, a nuclear energy expert at Segra Capital Management and Veriten. He did his senior project at the University of Florida on the subject in 2007 and remembers his professors arguing about the future of the technology even then.

There are 93 commercial nuclear reactors at 55 operating sites in the United States, according to Scott Burnell, spokesperson for the Nuclear Regulatory Commission. Twenty-six are in some stage of decommissioning process. All of the nuclear reactors that operate in the U.S. are light-water reactor designs, Burnell told CNBC.

In a light-water reactor, uranium-235 fuel powers a fission reaction, where the nucleus of an atom splits into smaller nuclei and releases energy. The energy heats water, creating steam which is used to power a generator and produce electricity.

The nuclear fission reaction leaves waste, which is radioactive and has to be maintained carefully. There are about 80,000 metric tonnes of used fuel from light-water nuclear reactors in the United States and the existing nuclear fleet produces approximately an additional 2,000 tons of used fuel each year, Gehin told CNBC.

But after a light-water reactor has run its reactor powered by uranium-235, there is still tremendous amount of energy potential still available in what is left.

“Fundamentally, in light-water reactors, out of the uranium we dig out of the ground, we use a half a percent of the energy that’s in the uranium that’s dug out of the ground,” Gehin told CNBC in a phone interview. “You can get a large fraction of that energy if you were to recycle the fuel through fast reactors.”

Fast reactors don’t slow down the neutrons that are released in the fission reaction, and faster neutrons beget more efficient fission reactions, Gehin told CNBC.

“Fast neutron reactors can more effectively convert uranium-238, which is…