COLUMBIA — With pressure building, the South Carolina Senate altered a plan Wednesday that gives state officials more time to sort out the $9 billion V.C. Summer nuclear fiasco.

After closed-door meetings, senators announced a plan giving lawmakers and the state's utility regulators until Dec. 21 to respond to the cancelled nuclear project in Fairfield County — now considered the largest financial failure in state history.

The plan could delay Dominion Energy's proposed takeover of SCANA Corp. and extend the clock for utility regulators on the Public Service Commission who are set to review the troubled power project.

Senators previously considered extending the utility commission's review period to February 2019 but decided Wednesday to try to resolve SCANA’s handling of the decade-long nuclear project by the end of the year.

The Senate’s proposal is likely to thwart SCANA's attempts to have the utility commissioners issue a decision about Dominion's takeover and SCANA's spending on the nuclear reactors by July.

The bipartisan group of lawmakers who asked for the delay said the public service commissioners and the Office of Regulatory Staff — the state's utility watchdog — need more time to vet SCANA's handling of the abandoned nuclear reactors.

The state utility agencies still need to investigate a variety of issues, including whether SCANA misled them during the decade-long project. Also, they need to determine if SCANA's spending and decisions at V.C. Summer were justified. And they need to study whether cutting off the $37 million per month that SCANA collects for the cancelled nuclear project will bankrupt the company.

After all of that, they still need to review Dominion's takeover. That deal would immediately reimburse SCANA customers $1.3 billion and charge them another $3.3 billion for the failed project over the next 20 years.

"I think it's important to remember this is almost certainly the most significant issue affecting South Carolina in my lifetime," said Senate Majority Leader Shane Massey, R-Edgefield.

The plan still has to be passed by the Senate and the House.

If it is approved, Dominion's hopes of closing its deal with SCANA by September will not happen. The plan may also throw more doubt into the minds of utility investors who already are showing skepticism about Dominion's ability to close the deal.

During a Senate hearing before the vote, Dominion CEO Thomas Farrell said he understood lawmakers' hesitations over deciding anything too quickly. But he also asked them not to delay things too long.

"I think you should absolutely be deliberate, but ... I think you need to move with all deliberate speed," Farrell said, quoting the Supreme Court decision in Brown v Board of Education, the famous case that integrated schools throughout the South.

Senate Minority Leader Nikki Setzler, D-West Columbia, said he wanted to resolve the fiasco, too. But with the monthly bills of more than 700,000 SCANA customers and the future of the state's energy industry hanging in the balance, he is not going to rush.

"We want finality, too, but we need the time to deal with this," Setzler said.

During the earlier Senate hearing, lawmakers also wanted to know how much Dominion stands to make from its proposed takeover of SCANA and the V.C. Summer nuclear project.

We're starting a weekly newsletter about the business stories that are shaping Charleston and South Carolina. Get ahead with us - it's free.

Massey asked Farrell about the 5 percent profit margin that Dominion is set to make if they are allowed to charge customers $3.3 billion for the unfinished reactors over the next 20 years.

Farrell didn’t specify how much money that would equal over the next two decades. But the 5 percent profit margin was a fair return, Farrell said, especially with the other benefits the company was offering. 

Massey, who led a special committee that investigated the nuclear cancellation, disagreed.

"Why is it fair that customers have to pay more than the debt, more than interest, so shareholders will get even more money?" he said.

If state officials don’t agree to the terms of Dominion’s deal, Farrell said the company will have to walk away, leaving SCANA financially weakened or possibly bankrupt.

SCANA’s credit rating was downgraded just last week to junk status. Farrell told lawmakers that ding to the company’s finances has already increased the borrowing costs for SCANA, one of the state’s largest publicly traded companies.

The Senate is expected to vote on its timeline for resolving SCANA’s handling of V.C. Summer on Thursday.

Reach Andrew Brown at 843-708-1830 or follow him on Twitter @andy_ed_brown.