For example, one megaton MEGA- A prefix denoting 1,000,000. means 1,000,000 tons. MONITORING The procedure or operation of locating and measuring radioactive contamination by means of survey instruments. Persons engaged in this activity are referred to as radiological monitors. NEUTRON One of the elementary particles of an atom. are uncharged and have a mass number of one. Neutrons They are used to initiate the fission process, and large numbers of them are produced in fission and fusion processes. They constitute a significant portion of the prompt radiation from both fission and fusion detonations. Neutrons travel great distances in the air and can readily penetrate most substances. NEVADA TEST SITE (NTS) The region in southeast Nevada set aside for the continental atmospheric nuclear weapons testing program. Known first as the Nevada Test Site, then as the Nevada Proving Ground (NPG) beginning in early 1952, the site since 1955 has again been called the NTS. NUCLEAR DETONATION A general name given to any explosion in which the’? energy released results from reactions involving atomic nuclei, either fission or fusion or both. NUCLEAR RADIATION Radiation emitted from unstable nuclei. Important nuclear radiations are alpha and beta particles, gamma rays, and neutrons. All nuclear radiations are ionizing radiations, but the reverse is not true. X-rays, for instance, are included among ionizing radiations, but they are not nuclear radiations since they do not originate from atomic nuclei. NUCLEAR TEST PERSONNEL REVIEW (NTPR) An organization established by the Defense Nuclear Agency to conduct a series of wide-ranging actions on behalf of U.S. atmospheric nuclear test participants and veterans of the postwar U.S. occupation of Hiroshima and Nagasaki, Japan. OFFSITE The area outside the boundaries of the Nevada Test Site. ONSITE The total area encompassed by the Nevada Test Site, including Camp Mercury, Frenchman Flat, Yucca Pass, and Yucca Flat. PROMPT RADIATION Radiation emitted from a nuclear detonation within a microsecond of detonation. It consists mainly of neutron and gamma radiation. 207