Study on the correlation between geological features and environmental radiation

Numerous data of gamma-ray total count rates have been accumulated during the past two decards by carborne gamma-ray survey which as carried out for the uranium exploration in Japan by Power Reactor and Nuclear Fuel Development Corporation (PNC). We describe a method to convert existing carbone data into absorbed dose rate and briefly review the new carbone system with twelve NaI(T1) cylindrical crystals which was introduced to convert previous data into absorbed dose rate because the previous carborne system does not exist at present. (author)