The Nuclear Regulatory Commission recommended a fine against the only nuclear plant in Kansas, finding Wolf Creek Nuclear Operating Corp. retaliated against a whistleblower who raised safety concerns during a planned facility shutdown.

The $232,000 civil penalty was proposed Dec. 18 against Wolf Creek, located in Burlington, Kan. Management’s decision to discipline a contract employee constituted a Severity Level II violation under NRC enforcement policy, the agency said.

The penalty relates to a September 2016 refueling outage during which a...