New London — Local, state and federal emergency preparedness teams performed “extremely well” during a safety drill Tuesday of their response to a simulated accident and radiation leak at the Millstone Power Station in Waterford.

That was the assessment given by Federal Emergency Management Agency officials during a post-exercise briefing at Fort Trumbull State Park.

“Our evaluators are very meticulous in their review, and they were extremely impressed with the attitude and effort and professionalism of all involved,” said Steve Colman, emergency management specialist with FEMA’s Region 1 office in Boston.

“The players did not know anything about the scenario beforehand," he said. "It did challenge them and they rose to the occasion.”

Colman delivered the assessment Friday afternoon to officials from the state Department of Emergency Services and Public Protection’s Division of Emergency Management and Homeland Security, the state Department of Energy and Environmental Protection, FEMA, the Nuclear Regulatory Commission and Millstone.

Earlier in the day, representatives of the nine towns in the Millstone Emergency Planning Zone who participated in the exercise also were briefed.

About 500 people from local, state and federal agencies and Millstone were involved in the exercise.

Colman said nuclear power plants and their surrounding communities are required participate in an evaluated exercise every two years.

The six-hour scenario simulated an “unusual event” at Millstone at 7:30 a.m. that prompted notification of local, state and federal emergency responders, said Steve Henrick, emergency management program specialist with the state Homeland Security division.

Once notified, the emergency responders began their response, which included dispatching field monitors to various locations outside the Waterford nuclear power plant with equipment to measure radiation levels released by the incident, Henrick said.

Other emergency response personnel worked out of dispatch centers in local towns, at the power plant and at Millstone’s new emergency operations facility in Norwich.

Henrick said the radiation detected was below the level that would have prompted an alert to residents to take potassium iodide pills, but residents in some areas would have been advised to evacuate.

Jeffrey Semancik, director of DEEP’s radiation division, said the evacuation area included neighborhoods within a two-mile radius of the plant in Waterford and East Lyme.

In addition to those two towns, the entire Emergency Planning Zone includes all or parts of New London, Montville, Old Lyme, Lyme, Groton, Fishers Island and Stonington.

Nineteen sites in the planning zone were evaluated for their response, with all performing positively overall, although FEMA officials did find some areas needing improvement.

Areas requiring improvement included a need for updating procedures used by teams doing field monitoring of radiation levels, better preparation for response to a siren failure, improved mapping of evacuation routes and better traffic control in some areas.

Sonny Stanley, director of nuclear safety and licensing at Millstone, said the participants performed well because they worked together effectively.

“The success of the exercise was achieved only with the teamwork and collaboration of all the players,” he said.

Written comments on the exercise can be sent to: FEMA, Region 1; Technological Hazards Branch; 99 High St., 5th Floor; Boston, MA 02110.

j.benson@theday.com