The Nuclear Regulatory Commission will conduct extra federal oversight for up to a year for the Unit 2 reactor at Millstone Power Station in Waterford following a mishandled power increase that occurred five months ago.

On Feb. 12, a reactor operator at Unit 2 accidentally caused an increase in power that his control room crew failed to prevent from escalating to an 8 percent increase before getting the surge under control.

Dominion, the parent company of Dominion Nuclear Connecticut, owns Millstone.

“While the NRC did not identify any impacts on plant safety due to the Feb. 12th event, the agency holds control room operators to the highest standards,” NRC Region I Administrator Bill Dean said in a statement.

“This inspection finding signals the need for plant personnel to step back and learn from this event in order to prevent it from occurring again.”

The incident did not pose safety concerns because the power increase never exceeded required limits and did not result in damaged fuel.

Dominion spokesman Ken Holt said the company has completed a thorough analysis, known as a root cause analysis, of the problems that day and has incorporated lessons learned into how operators handle critical equipment readings in the control room.

“We remain extremely disappointed with our performance during this event,” Holt said. “Nuclear safety is our top priority. We have learned from this event and have taken actions to ensure we don’t repeat it.”