Abstract
AMS/NEST (Aerial Measurement System/Nuclear Emergency Search Team) executed emergency radiation monitoring using aircrafts at the time of the nuclear accident occurred at Three Mile Island-II reactor, U. S. A. in 1979. Motivated by this activity, Japan Atomic Energy Research Institute started a series of research and development of aerial survey system in 1980, and completed it in 1985. This system was named ARSAS (Aerial Radiological Survey and Assessment System).
ARSAS, loaded on board a helicopter, can measure wide range of gamma radiation field (10nGy/h-10mGy/h) and position of the helicopter. These data are recorded at every second without lack of acquisition. Using this system, one can get useful data for emergency countermeasures, such as isopleth map of dose rates, information about the direction of radioactive plume, release rate of radionuclides from the stack, and so on. This article mentions about the outline of ARSAS.
