1.   Researchers have also placed ultraviolet radiation sensors on the ground to see if there is an increase as the plume passes between the Sun and the ground.

2.   Sen. Larry Craig said radiation sensors were used at the Salt Lake Olympic Games and the Super Bowl in New Orleans.

3.   Sen. John McCain said Sunday he was unfamiliar with the deployment of newer radiation sensors.

4.   The U.S. government, meanwhile, has dispatched hundreds of radiation sensors to U.S. border crossings and transportation hubs, and the IAEA is working to install them internationally.