Scientists Keep Radiation in Its Place

There are two types of radiation: non-ionizing radiation, from sources such as visible light and radio waves, and ionizing radiation, from radioactive materials or x-ray equipment. Ionizing radiation can be harmful to humans -- but it can also be useful. Nuclear reactors use a process called fission to release the energy stored in radioactive materials like uranium. That energy powers all Navy aircraft carriers and submarines. The reactors are carefully shielded to prevent radiation from leaking out -- but since ionizing radiation can damage cells, sailors who work near the reactors need to be protected. So engineers at NAVSEA Carderock in Bethesda, Md., are researching and testing devices that monitor radiation.