The drill was conducted alongside normal operations and did not involve changes to actual generating and transmission equipment.

The drill, which began just after 7 P.M. and lasted about two hours, involved members of the police and fire departments and the Emergency Medical Service.

The drill involved at least 20,000 troops, up to 70 warplanes and 30 warships.

He confirmed that the drill involves no penalties, and said that the agency would decide whether to publicize the results.

The drill, a test of water-survival skills, involves jumping from a copter, swimming to a raft and paddling it to a waiting boat.

The drill involved faking the deliberate crash of a plane into the plant, but it was limited to communications drills, without live road blockades or attempts to simulate evacuations in the outside world.

But, according to David Gruber, New Jersey's assistant health commissioner, drills at other hospitals may now involve only "three people sitting in a room, sharing information with each other, with no follow-up."

The drill today will involve hundreds of city, state and Federal law enforcement officers.

One drill involved holding an umbrella under his armpits while striking putts.

But an Israeli Army spokesman noted that the drill involved only a simulated traffic accident.