The g2microven and some new microwaves from other manufacturers, however, use an inverter magnetron that allow them to reduce the level of radiation being produced within the oven.
It was established that the radiation being emitted was electrons, because the measurement of the emitted particles' charge and mass was exactly the same as for electrons.
Top officials from American health agencies said this week that Americans are in no danger from the trace amounts of radiation being detected in this country's air, water or food supplies.
"When tritium gets into the environment and it's on top of radiation being released from other parts of the laboratory, it potentially increases the dose and potentially increases the risk," Ms. Kelley said.
Critics of the plant and its evacuation plan called the drill nothing more than hollow play-acting and said it was unlikely that a plane crash would have resulted in no radiation being released outside the plant, as the drill specifiedl.
While maps of the plume of radiation being given off by the plant show that an elongated cloud will stretch across the Pacific, American officials said it would be so dissipated by the time it reached the West Coast of the United States that it would not pose a health threat.
