Leakpath Factor: The fraction of the radionuclides in the aerosol transported through some
confinement deposition of filtration mechanism.
Level of Concern: The concentration of an extremely hazardous substance in air above which
there may be serious irreversible health effects or death as a result of a single exposure for a
relatively short period of time.
Local Response or Damage: Penetration and spalling, scabbing, punching shear, and
perforation of building structural components (e.g., a wall or floor) that may not result in the
overall failure or collapse of the whole building structure.
Low Altitude (Victor) Route: The designated route between VOR or VORTAC stations for
aircraft flying at or below 5486 m or 5.5 km (18,000 ft) MSL.
Material at Risk (MAR): The amount of radionuclides available to be acted on by a given
Military Aviation: As used in this standard, the aircraft category pertaining to any aircraft
activity performed by the U.S. Air Force (USAF), U.S. Navy (USN), U.S. Marine Corps (USMC),
U.S. Army (USA), and the U.S. Coast Guard (USCG).
Missile: A general term used to denote both primary and secondary missiles. See also
"primary missile" and "secondary missile."
Near-Airport Analysis: The aircraft crash impact frequency analysis involving the airport flight
phases (takeoff and landing) for aircraft using airports within specified distances from a facility.
Nonairport Analysis: The aircraft crash impact frequency analysis involving aircraft in the
in-flight flight phase.