County Sheriff James Moore told local news station WTOK that the contractor electrician for firm ISC suffered an electric burn Monday morning.
The badly injured male worker was airlifted from the facility after the incident.
Mississippi Power spokesman Jeff Shepard told the station the man was stabilized before leaving the plant, but no further information was available on his condition Tuesday.
Mississippi Power is a subsidiary of Southern Company.
The company is developing the 582-megawatt integrated gasification combined cycle Kemper facility near Meridian.
The $5 billion project is currently scheduled to come online next May.
