The U.S. Nuclear Regulatory Commission on Wednesday said it had cited Xcel Energy Inc. for a security violation at its Prairie Island nuclear power plant in Red Wing, but it released few details.

Xcel, in an e-mailed statement, said the problem, which the NRC began investigating last May, involved a contract employee who no longer is with the utility.

“There was never any harm or risk to plant employees or the public or the operation of the plant,” said Xcel spokesman Tom Hoen.

The NRC said the security violation was a willful act by one employee, was reported by Xcel to the agency and was immediately corrected. Xcel has been told to describe what changes it made to broadly address the concern.

David Shaffer