The U.S. Energy Department is throwing its support behind a request by utilities to extend the life of some nuclear power reactors — keeping them in operation for as long as 80 years.

An official with the department, who asked not to be named to discuss its decision-making process, said the agency was conducting research and working with utilities seeking permission from the Nuclear Regulatory Commission to allow reactors built in the 1970s to keep operating to 2050 and beyond.

Already, the utilities Exelon Corp., and Dominion Energy Inc. and NextEra Energy Inc. have said they plan to ask regulators to extend 60-year licenses by 20 years for eight reactors in Virginia, Pennsylvania, and Florida. Requests for as many as 20 more are expected to follow, according to the nuclear industry.

The plans have already raised the ire of anti-nuclear campaigners, who cite decades of wear and tear on the nation’s reactors, as well as the 2011 Fukushima disaster in Japan.

Nuclear power accounts for about 20 percent of electricity generated in the U.S. but competition from cheap natural gas, subsidized renewable power and stagnant electricity demand has led to a wave of uneconomical nuclear reactors being retired years earlier than planned.

President Donald Trump began a review in June of ways to revitalize the nation’s nuclear industry. Ultimately, the decision on extending the operating license of a reactor lies in the hands of the independent Nuclear Regulatory Commission, but the industry says the help is appreciated.

“You are talking about continuing the operation of a perfectly safe and reliable power plant. Make that comparison with the new construction of a plant,” said Jerud Hanson of the Nuclear Energy Institute, a lobbying group. “The cost savings are substantial.”

The costs of retrofitting an existing plant can vary, on a case-by-case scenario, but are likely to be in the hundreds of millions of dollars, he said. Construction of a new plant runs well into the billions.

Southern Co., which is building two reactors in eastern Georgia, the first new American nuclear project to be approved in three decades, has seen the cost estimates double to more than $25 billion.

Of course, keeping a nuclear reactor running beyond the average life of a human being — something that Barack Obama’s energy secretary also advocated — has its detractors.

“That’s kind of crazy,” said Tyson Slocum, director of the energy program for the Washington-based watchdog group Public Citizen. “These facilities were not designed to operate that long. The longer you extend the operating life of these facilities the more things can go wrong.”

Already, a majority of the 99 commercial nuclear reactors operating in the U.S. have sought and received permission by the Nuclear Regulatory Commission to extend their licenses from 40 to 60 years.

Others say that allowing a nuclear reactor to operate for 80 years doesn’t address the underlying economic headwinds.

“What you are seeing with extending the license is companies preserving an option, but it’s an option that very few will likely exercise,” said Peter Bradford, a former member of the NRC. “Unless the federal government is somehow prepared to either put taxpayer dollars into steam generator replacements or to somehow mandate that the customers have to pay for it, it’s just not going to happen.”