[en] The radioactive waste temporary storage in Malaysian Nuclear Agency is to store waste that obtained from extraction of monazite and rare earth mineral in order to produce thorium. Hence, the waste temporary storage shall follow safety, security and safeguard guideline. One of the criteria in designing the radioactive waste temporary storage is ventilation system that can control the temperature and humidity level in order to ensure radioactive waste in good condition. The objective of this research is to design the ventilation system for portable cabin as a temporary storage for radioactive waste that obtained from thorium extraction process. The output of this research is important to ensure ventilation system was designed as per good engineering practice in order to ensure temperature and humidity level in radioactive waste temporary storage as per design requirement. (author)