VC Summer Jan 31 2018 IMG_3575.jpg (copy) (copy)

An aerial shows the the V.C. Summer nuclear project. File/High Flyer/Provided

A team of FBI agents visited the unfinished reactors at V.C. Summer Nuclear Station this month, marking one of the most visible actions yet by federal investigators probing the failed project.

The Office of Regulatory Staff, the state’s utility watchdog agency, says that as many as 19 FBI agents went to the nuclear plant last week, and they stayed for multiple days. They were helping with a U.S. Department of Justice investigation into the project.

The agency says the FBI visit was disclosed as part of an internal meeting it attended last week, alongside presentations about what to do with leftover parts from the $9 billion project that collapsed last summer.

The FBI’s field office in Columbia declined to confirm whether it had been to the V.C. Summer site. Santee Cooper, the minority owner of the project, couldn’t be reached for comment on the FBI visit. South Carolina Electric & Gas, the majority owner, said it gave agents access to the site voluntarily.

"SCE&G is cooperating fully with the ongoing investigations," spokesman Eric Boomhower said in an email. "We have been in regular contact with the agencies involved and have voluntarily provided them with access to the nuclear construction site."

The federal probe into South Carolina’s nuclear failure has stayed under the radar since investigators subpoenaed documents from SCE&G and Santee Cooper. It’s thought to parallel a state law enforcement investigation and a review by the U.S. Securities and Exchange Commission.

Investigators last year asked the power companies to hand over documents about a highly critical audit of the project’s viability. The so-called Bechtel report raised alarms in 2015 that the new reactors at V.C. Summer were years behind schedule because of construction issues, faulty designs and incomplete engineering work.

The same audit has been central to legal arguments seeking to force the utilities to bear the cost of the construction project. A raft of lawsuits accuse the power companies of hiding problems from investors, regulators and ratepayers who are paying for the reactors.

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Still, it's not clear whether the federal investigation's scope has shifted since subpoenas were first issued in September. Internal documents reviewed by The Post and Courier show that the utilities harbored concerns about the project’s viability years earlier.

South Carolina lawmakers asked state investigators to open their own review days after the newspaper reported that the project didn't use licensed engineers for the reactors' designs.

Construction wasn’t called off until July after lead contractor Westinghouse Electric filed for bankruptcy under the weight of the project’s mounting costs.

About a fifth of SCE&G ratepayers’ monthly bills is earmarked for the nuclear project. About 5 percent of Santee Cooper’s electricity rates are tied to the project, but prices are expected to rise over the next several years as more debt comes due.

Andrew Brown contributed to this report from Columbia.

Reach Thad Moore at 843-937-5703. Follow him on Twitter @thadmoore.