In the United States, spent fuel became the responsibility of the federal government, specifically the Energy Department, subjecting the issue to more political pressures.
At the Onkalo site, workers drill into the bedrock down near the 1,400-foot level, taking cores to study the characteristics of the granite. Above ground, near the curving entrance to the tunnel, construction has begun on a building where the spent fuel, currently cooling in pools at the Olkiluoto reactors, will be readied for burial, handled by remote-controlled machinery since radiation levels will be high. Spent fuel will also eventually be shipped here from Fortum’s reactors, on the country’s southeastern coast.
Kimmo Kemppainen, research manager for the project, said that in characterizing and mapping the rock, it was important to locate, and avoid, fractures where water could flow, since the disposal site was below the water table. But even if water gets near a canister, he said, the clay should form a barrier and keep corrosion of the copper — which could result in a radiation leak — to a minimum, even over tens of thousands of years.
Mr. Kemppainien has worked on the project for 14 years. “My personal opinion is that for this generation that has used nuclear power, at least we should do something about the waste,” he said. “It’s not safe to store it on the surface.”
In the United States, more than 80,000 tons of spent fuel are currently stored on the surface, in pools or dry steel-and-concrete casks, at operating nuclear reactors and at other sites near now-closed plants. The original deadline to have a repository operating by 1998 is long past.
The project at Yucca Mountain, in the Mojave Desert about 100 miles northwest of Las Vegas, has been studied for years at a cost of more than $13 billion. In 2008, the Energy Department began the process of obtaining a construction license from the Nuclear Regulatory Commission. But the Obama administration moved to withdraw the license application two years later.
With the election of President Trump, advocates for Yucca Mountain saw a chance to revive it.
“This is a very important national project,” said Rod McCullum, a senior director at the Nuclear Energy Institute, an industry group. “If we can do this safely, we would be ashamed of ourselves if we didn’t do it.”
The Trump administration is seeking $120 million to reopen the licensing process. And in a symbolic gesture, in his first official trip as energy secretary, Rick Perry toured the site, where little exists beyond a five-mile-long exploratory tunnel.
Congress rejected the licensing funds in its deliberations on the 2017 budget, and the 2018 budget process is just starting. Even if the $120 million is allocated, it could take a half-decade or longer, and much more money, to complete the licensing, which would involve a lengthy hearing before administrative judges on hundreds of environmental and safety issues raised by opponents.
Even without Mr. Reid, most members of Nevada’s congressional delegation are still vowing to fight the project, arguing that there are concerns about the long-term safety of drinking water supplies — unlike the Finnish repository, the Nevada site sits above the water table — and that above all, Nevadans do not want it.
“The main issue is consent,” she said. She and other members of the delegation have introduced a bill that would require the host state’s approval before the repository could be built.
In a 2012 report, an expert panel established by the Obama administration to develop a new strategy for managing spent fuel recommended a similar consent-based process. It had another Finland-like recommendation as well: that responsibility for nuclear waste be taken from the Energy Department and put in the hands of an organization created solely for that purpose.
Those recommendations have not been acted upon. But it is also unclear whether Yucca Mountain, if revived by the Trump administration, would succeed under the current approach.
“It could be that the federal government could prevail and after some decades we would have a repository,” Dr. Ewing said. “It could be that after several decades the federal government could fail and we would be where we are at today.”
There’s a lot to be said for how Finland handled its situation, Dr. Ewing added. “If you treat people fairly and present them the information, if the repository is safe, you should be able to get some communities to respond positively,” he said.