It would be more forceful and perhaps longer lasting if Congress passed a law to do these things. Merely imposing an EPA regulation means that some future administration could reverse the policy. Doing it this way might also make it easier to challenge in the courts.
The Environmental Protection Agency as soon as this week is expected to unveil standards for new and existing power plants, which belch roughly a quarter of U.S. greenhouse gas emissions, two sources said. The rules will replace former President Donald Trump’s American Clean Energy rule and former President Barack Obama’s Clean Power Plan, both of which were invalidated by courts.
More than a year in the making, the standards should be based on a plant’s potential to reduce emissions through carbon capture and storage (CCS) technology, according to clean air law experts and industry representatives in talks with the EPA.
^ ^ ^ ^ ^ ^
If these CCS rules are implemented, that would make nuclear look better in comparison to provide the baseload 24/7 power that the grid requires.