The Chattanooga Times Free Press reported the Tennessee Valley Authority's Browns Ferry Nuclear Plant in northern Alabama also had several internal complaints.
The NRC report showed there were 21 complaints against Watts Bar, 19 on Sequoyah and 16 at Browns Ferry in 2012.
TVA spokesman Mike Bradley said the utility took action after conducting its own analysis for the NRC.
Bradley said some new hires during a steam generator replacement project at Sequoyah didn't use in-house complaints, but went directly to the NRC, causing a spike in the number.
He said at Watts Bar, confusion over a change in work-ready status sparked complaints.
Information from: Chattanooga Times Free Press, http://www.timesfreepress.com
Copyright 2013 The Associated Press.