The Trump administration will finalize $3.7 billion in loan guarantees to Southern Co. and its partners who are building a troubled nuclear reactor project in Georgia — the last of its kind under construction in the U.S. — according to two people familiar with the matter.

The guarantees, expected to be announced Friday when U.S. Energy Secretary Rick Perry visits Plant Vogtle alongside Georgia Governor Brian Kemp and Southern Chief Executive Officer Tom Fanning, represents a critical lifeline for the project, which is more than five years behind schedule and has doubled in cost to $28 billion.

The additional help also puts taxpayers on the hook for more money if the project were to collapse. Southern and its partners in Plant Vogtle were already recipients of record $8.3 billion in federally-backed loan guarantees from the Obama administration, but asked the Trump administration to come to their aid amid ballooning costs and setbacks caused in part by the bankruptcy of a contractor, Westinghouse Electric Co.

The plant, near Waynesboro, Georgia, is seen as critical to the nuclear industry’s future because existing reactors are struggling to compete with cheap natural gas and renewable energy. Scana Corp. abandoned its plans to build two reactors in South Carolina after expenses spiraled above $20 billion.

President Donald Trump has made the revival of the coal and nuclear industry a priority. His administration in 2017 announced it would provide a conditional loan guarantee for the Plant Vogtle project.

Representatives of the Energy Department and Southern didn’t immediately respond to requests for comments.