If any radiation escaped into the air, officials said, the levels were so low as to pose no health risks.

The accident had, after all, been contained and little radiation had escaped.

Much of this tempestuous activity takes place far enough from the black hole that the radiation can escape.

Objects and radiation can escape normally from the ergosphere.

Officials said testing procedures had since been changed to make sure radiation does not escape.

Officials stressed that no radiation had escaped into the atmosphere and there was no danger to the environment.

As word came that radiation had escaped, they worked the phones and went through the motions of an evacuation.

Until today's statement, American officials offered no indication that radiation had escaped during the accident.

The rest had been buried so deeply that neither radiation nor heat had yet escaped.

Potential purchasers were particularly anxious that radiation would somehow escape through the oven walls or door.