Nuclear Power Station (copy) (copy)

Federal investigators have requested documents from Westinghouse, the contractor on South Carolina's nuclear project. File/Grace Beahm/Staff

Federal prosecutors have asked the contractor behind South Carolina’s failed nuclear project for documents as part of their probe, signaling that the months-long investigation hasn’t cooled off yet.

Attorneys for Westinghouse Electric, which was tasked with building a pair of reactors north of Columbia, disclosed the request in a court filing this week. They offered little detail about what prosecutors were looking for.

The request appears in the bills lawyers filed for their work representing Westinghouse. Throughout June, they fielded requests and addressed “questions raised by AUSA,” a common abbreviation for an assistant U.S. Attorney.

The bills suggest that Westinghouse handed over documents in the middle of June, just one month after FBI agents visited the emptied construction site at V.C. Summer Nuclear Station.

Westinghouse declined to comment on what it handed over to investigators. A spokesman for the U.S. Attorney’s Office for South Carolina didn’t respond to a request for comment.

The U.S. Attorney’s Office and the FBI have been involved with South Carolina’s nuclear debacle for nearly a year, opening an investigation after construction on the V.C. Summer project was called off. They’ve since been joined by the staff of the U.S. Securities and Exchange Commission, which oversees the stock market and public bond investments.

The SEC and FBI have served subpoenas on the utilities that own the nuclear project — South Carolina Electric & Gas and Santee Cooper — and they appeared to probe how the power companies handled a long-secret bombshell audit of problems with construction. It’s not clear if investigators have moved on to other aspects of the project.

Even so, investigators have left few tracks publicly aside from this summer’s site visit. Santee Cooper, for instance, says it hasn’t received any requests for documents since March. SCE&G declined to comment on the details of the investigation.

No one has been charged with wrongdoing as part of the federal investigations, but they parallel a slew of lawsuits and regulatory processes that have begun to shed light on what went wrong with the V.C. Summer project — and who knew about the problems.

The cases affect ratepayers who get their electricity from SCE&G, Santee Cooper and the state’s electric cooperatives — in all, about two-thirds of South Carolinians.

Electricity users are expected to pay for the $9 billion project for decades. The unfinished reactors have accounted for nearly a fifth of SCE&G’s electricity rates, and they eat up about 5 percent of Santee Cooper’s rates, a number that’s expected to rise over the next several years.

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