MONTICELLO (AP) - Federal regulators will continue increased oversight at Xcel Energy's Monticello nuclear plant after a security issue was found.

Issues that led to the problem spotted in the last quarter of 2014 have been resolved.  The U.S. Nuclear Regulatory Commission says those improvements mean it won't move the Monticello plant into a category of plants with the most serious performance issues. It did not release details of the violation.

The federal commission stepped up inspections in 2013 after it found that the Monticello plant wasn't ready for worst-case flooding along the Mississippi River.

Pete Gardner, the plant's vice president, says the security issue was found by plant workers. He says they corrected it and notified federal regulators.