For SCANA stock holders and employees, this could be chilling news.

State tax collectors want $297 million in unpaid sales taxes on SCANA’s $9 billion nuclear power plant.

The state Department of Revenue is auditing the Lexington County-based holding company and taxpayer-owned Santee Cooper, according to the Charleston Post and Courier.

State auditors say the two owe sales taxes on unfinished nuclear reactor parts.

The materials would have been tax-exempt if the plant was completed and producing power at the lower costs SCANA promised.

The audit appears to center on a line in state tax law that exempts major manufacturers from paying sales tax on their factories.

That could have covered the new nuclear reactors if they were operating.

Both utilities had promised state lawmakers, their investors and 700,000 ratepayers the project would save them billions of dollars.

The S.C. Department of Revenue has indicated to SCANA, the owner of SC Electric & Gas, that the scuttled reactors aren’t exempt because they “will not be placed into service and no electricity will be manufactured for sale,” the company told investors last week.

The estimated $9 billion cost of the nuclear project suggests that the tax bill could be enormous.

A 6% sales tax on $9 billion would be $540 million.

As 55% owner, SCANA could be charged $297 million and Santee Cooper $243 million. The latter could affect Mid-Carolina Electric Co-op members who buy Santee Cooper power.

Santee Cooper has told investors who own its bonds that the agency is looking at the materials sunk into the project — the turbines, steel and concrete that were meant to spark a nuclear renaissance in America.

Tax officials said “sales taxes were due on the previously tax exempt purchases,” according to Santee Cooper’s annual report.