Already, more than 90,000 metric tons of spent nuclear fuel is being stored at sites in 39 states. These include 73 commercial nuclear power plants and more than three dozen university and government facilities, according to a 2024 report by the Pacific Northwest National Laboratory.
The waste has accumulated in spent-fuel pools and dry casks intended for temporary storage since the U.S. nuclear industry began to take off in the 1960s, and the DOE’s failure to permanently dispose of the waste as required by law has cost taxpayers tens of billions of dollars to compensate the utilities.
New efforts to store nuclear waste away from reactor sites are also getting pushback. On Wednesday, the Supreme Court will hear arguments in a case that will determine whether private companies can temporarily store spent fuel at facilities in Texas and New Mexico.
State officials and others have argued that the Nuclear Regulatory Commission exceeded its authority when it granted licenses for the facilities. A decision isn’t expected in the case until later this year.
Meanwhile, nuclear reactors continue to provide almost 20% of U.S. electricity and produce about 2,000 metric tons of waste each year. As additional plants become available to meet the demands of data centers, industrial plants, homes and electric vehicles, the waste pile is poised to grow even more.
The nation’s first new reactors in three decades were completed last year in Georgia. Plans are in the works to reopen closed reactors in Michigan, Iowa, Pennsylvania and South Carolina.
And President Trump has pledged to fast-track permits for new kinds of small modular nuclear reactors that are still being developed.
Nuclear power is attractive because it produces virtually no greenhouse gases and offers a nearly uninterrupted flow of electricity. But the radioactive waste it produces should be permanently stored deep underground, according to interviews with scientists and engineers.
“It is irresponsible to go forward and build new reactors if you haven’t solved the waste problem,” said Allison Macfarlane, who chaired the U.S. Nuclear Regulatory Commission from 2012 to 2014 and is now director of the School of Public Policy and Global Affairs at the University of British Columbia.
Other nuclear-powered nations are moving faster to build waste repositories.
Finland is completing final testing on an underground site—1,500 feet below a forest in the southwestern part of the country—that is expected to open in 2026. The country has five reactors that generate about one-third of its power.
France generates 70% of its electricity from nuclear energy, recycles about 96% of its waste into new fuel and stores the remainder in a centralized cooling pool in Normandy. French officials expect to start construction in 2027 on a permanent underground repository in northeastern France to open by 2035.
In November, Canadian officials selected a permanent site for nuclear waste to be dug out of bedrock in northwestern Ontario.
But U.S. efforts stalled decades ago, when a $15 billion project to build a permanent, underground storage facility at Yucca Mountain, Nevada, was halted amid opposition by elected officials in the state, according to a 2021 report by the Government Accountability Office.
The Yucca Mountain failure cast a shadow over efforts to build a permanent disposal site, according to interviews with nuclear experts, policymakers and elected officials.
“There are no technical issues, there are no engineering issues,” said Paul Murray, the DOE’s deputy assistant secretary for spent fuel and high-level waste disposition, during a Nov. 26 webinar sponsored by the agency. “What we’re trying to do is really try to establish a public trust and political will to actually do something. We’ve done all the studies we need to do.”
Until a permanent storage facility is built, Interim Storage Partners, a joint venture between Orano USA, a nuclear decommissioning firm, and Waste Control Specialists, a Texas disposal company, has proposed temporarily storing up to 40,000 metric tons of spent nuclear fuel aboveground in dry casks at a facility in Texas that currently holds low-level radioactive waste.
Separately, Holtec International, a nuclear engineering services company, proposed a below-ground storage facility for dry casks in New Mexico, about 40 miles away from the Texas facility, that could store up 8,680 metric tons of spent nuclear fuel.
In 2023, a federal circuit court, siding with Texas officials and other opponents, found that the NRC exceeded its authority in granting a license to allow Interim Storage Partners to store nuclear waste at its site for 40 years, with the possibility of extending the license. The same court blocked Holtec’s NRC license for an interim storage site in New Mexico in 2024.
The Supreme Court will hear the NRC’s appeal of the Texas decision on Wednesday. The high court’s ruling will also determine whether the New Mexico site can move forward.
Even if these temporary sites are built, some elements of spent fuel stay radioactive for thousands of years, and federal law requires permanent storage to last 10,000 years. That means a permanent geological repository—somewhere deep, dry and far from active earthquake faults—will still be needed.
A typical nuclear reactor holds 121 to 193 fuel assemblies that house 12-foot-long uranium fuel rods, according to the U.S. Energy Information Administration. Each assembly has 179 to 264 fuel rods. After five to seven years, the uranium begins to degrade, and every 18 months, about a third of the fuel assemblies are moved from the reactor to a spent-fuel pool.
A typical pool is about 40 feet deep and can be 40 or more feet square. The walls are four-feet thick to eight-feet thick reinforced concrete lined with stainless steel. Waste is stored under at least 20 feet of water.
As the pools fill up, spent fuel assemblies are transferred to dry casks.
Casks manufactured by Holtec International inside a huge factory just across the Delaware River from downtown Philadelphia consist of stainless steel canisters nested inside thicker carbon-steel outer shells with two feet of concrete poured in between. The entire unit weighs 360,000 pounds and can hold up to 89 spent fuel assemblies. By comparison, spent fuel pools can hold up to several thousand spent fuel assemblies.
By law, the Energy Department is required to accept and store spent nuclear fuel, but because a permanent disposal facility has never been completed, the government pays utilities $600 million to $800 million each year in damages for failing to dispose of the waste.
The DOE has paid utilities $11.1 billion in damages since 1998. The agency’s future liability for waste disposal is projected to reach up to $44.5 billion, according to a 2024 audit by the DOE’s Office of Inspector General.
“We are going to need more nuclear energy,” said Rep. August Pfluger (R., Texas), who has co-sponsored legislation to set up a new agency to find a permanent disposal site. “But we do have a problem with waste.”
(“The Wall Street Journal”, March 5, 2025)