President-elect Donald Trump’s advisers are looking at ways in which the U.S. government could help nuclear power generators being forced out of the electricity market by cheaper natural gas and renewable resources.

In a document obtained by Bloomberg, Trump’s transition team asked the Energy Department how it can help keep nuclear reactors “operating as part of the nation’s infrastructure” and what it could do to prevent the shutdown of plants.

Advisers also asked the agency whether there were any statutory restrictions in resuming work on Yucca Mountain, a proposed federal depository for nuclear waste in Nevada that was abandoned by the Obama administration.

The list of questions to the Energy Department offers one of the clearest indications yet of Trump’s potential plans for aiding America’s battered nuclear power generators. Five of the country’s nuclear plants have closed in the past five years, based on Energy Department data, and more are set to shut as cheaper supplies from gas-fired plants, wind and solar squeeze their profits.

Media representatives for the Trump transition and Energy Department didn’t immediately respond to calls and emails seeking comment.

Some environmentalists have warned the closures could undermine efforts to combat climate change as nuclear reactors are the biggest source of zero-emissions power in the U.S. Plant owners including the nation’s largest — Exelon Corp. — have sought relief from state policymakers, with New York and Illinois among those that have approved millions in annual payments to keep reactors running.

Exelon rose 1.4 percent to $34.69 at 11:03 a.m. in New York. The shares are up 25 percent this year.

The Trump administration could find that providing “federal subsidies and programs to boost the struggling industry may be elusive and contentious,” Rob Barnett and Kit Konolige, analysts at Bloomberg Intelligence, wrote Friday in a research note. House Republicans could balk at incentives at the federal level, they said.

Among a list of questions the Trump team sent to the Energy Department was whether the agency has plans to resume the license proceedings for Yucca Mountain and how it can continue supporting the permitting of small modular reactors, seen as the next generation of nuclear technology.

On Thursday, Entergy Corp. announced that it’ll shut the Palisades nuclear plant in Michigan in 2018, adding to the growing list of reactors planning to retire early.

Trump has voiced his support for nuclear power in the past. In a television interview with Fox News in 2011, he said he was “very strongly in favor of nuclear energy,” while stressing the need for safeguards at plants.

Last month, the Washington trade group Nuclear Energy Institute congratulated Trump on the election and encouraged him to advance his support for the industry and maintain “its indispensable role in our critical energy infrastructure and environmental interests.”