In the PWR nuclear power plant, radioactive gas continuously extracted from the primary coolant is reduced by decay in the long-term storage tank before being discharged into the environment. A new radioactive waste gas treatment system using a charcoal bed is expected to reduce the amount of radioactivity released and simplify the system, while improving system reliability, operation and maintenance. A charcoal bed-type of radioactive gas removal system has been designed and built based on fundamental test data, and the system gradually introduced into new plants has been operated stably. This paper introduces an outline of the system, together with an outline of the fundamental test results and dynamic simulations.