Dive Brief:

• The Department of Energy (DOE) on Friday urged owners of the sole nuclear plant under construction in the United States not to cancel the project ahead of a Monday vote that could determine its fate.

• Minority owners of the Vogtle nuclear project in Georgia are weighing whether to pull out of an expansion of the plant, which is billions over budget and years behind schedule. DOE warned that would prompt the repayment of billions in federal loans and strike a blow to the fragile U.S. nuclear industry.

• Last month, majority owner Southern Co. notified municipal utility partners they would have to contribute an additional $2.3 billion to complete the project, bringing the total cost to $27 billion. The new charges triggered a clause in the agreement where 90% of the ownership must agree to move forward with the project.

Dive Insight:

Monday's vote on the Vogtle project could mark the end for the troubled plant expansion, but the DOE's correspondence makes clear the stakes are bigger than a single generation project.

In letters released late Friday, DOE said it understands that the choice to continue Vogtle is a "commercial decision," but warned that it would have a "profound impact on the U.S. nuclear industry" and leave a "reputational mark of American industry to complete important and complex infrastructure projects."

If Vogtle is completed, it will be the first nuclear plant built in the U.S. in more than three decades, and DOE called it a "linchpin" in the president's energy strategy.

"The decision each owner makes should be made with an understanding of the ripple effect this project is already having, including job creation and the positive signal of the continued value of commercial nuclear power in our country," John Sneed, executive director of the DOE Loan Programs Office, wrote.

DOE has already paid out $5.6 billion of an $8.3 billion federal loan guarantee, Sneed reminded owners, and an additional $3.7 billion will be made available by the Trump administration if the project moves forward.

If it is canceled, DOE "will move to fully enforce its rights under the terms of the Loan Guarantee Agreements to ensure the true guarantors of those funds … are made whole," DOE wrote.

Southern subsidiary Georgia Power owns nearly half of the Vogtle plant, along with Oglethorpe Power Corporation (30%), Municipal Electric Authority of Georgia (MEAG) (22.7%) and Dalton Utilities (1.6%). Georgia Power is expected to vote to finish the project, but a no vote from Oglethorpe or MEAG could force it to a halt.

Proposed in 2008, the two-unit expansion of the plant near Augusta, Ga., was originally supposed to cost about $14 billion, but problems with its new reactor design led to construction delays and cost overruns. Utilities in South Carolina abandoned a similar project — the V.C. Summer plant expansion — over the same issues last year.

One municipal utility is already trying to sever its ties with the Vogtle project over rising costs. Last month, the Jacksonville Electric Authority (JEA) sued MEAG, asking a judge to invalidate a 2008 power purchase agreement the Florida muni signed with the plant owner. MEAG sued back, and last week JEA asked the Federal Energy Regulatory Commission to intervene.

In addition to DOE, Gov. Nathan Deal, R-Ga., also urged owners to complete the plant in a letter last week, the AP reports.

"Given the project's critical economic impact to the State of Georgia, I strongly encourage [the project's] co-owners to continue work and complete the construction," Deal said. "I am counting on the project co-owners to follow through on the commitments you made to the citizens of Georgia, ratepayers and myself."