Design of negative pressure ventilation systems for radiation area of CSNS

China Scattered Neutron Source (CSNS) is the first of the twelve major scientific devices to be built during the national Eleventh Five-Year Plan period, and is a high-tech, multidisciplinary, large-scale research platform located at the international forefront. The project includes an underground accelerator tunnel and a target station, where a large amount of radioactive material is generated during the operation of the process equipment. In addition to meeting the temperature and humidity requirements of the process equipment, it is important to ensure that the radiation area is sealed and under negative pressure during the operation of the process equipment, and that the air in the radiation area does not leak out until it has been treated to meet the emission standards. This paper presents the ventilation design requirements and system design scheme for the project, which provides a reference for the design of negative pressure ventilation systems for radioactive space of such large scientific installations.