The requirements for radiation monitoring from an integrated instrumentation system aspect are developed with emphasis on the detection and control of radiation hazards. General treatment is given to the problems and equipment involved in operational or process monitoring, site monitoring, effluent monitoring and area or personnel monitoring. The types of radiation that are encountered in a nuclear plant and the units of measurement that are used are discussed. A review of the types of monitoring equipment that are presently available to make plant and personnel measurements and their sensitivity and reliability as related to meeting accepted standards for plant personnel and general public protection is given. A typical radiation monitoring system and the basis for the design are described. A brief summary of the status of development of solid state monitors is included.