Oily sludge waste could be included Naturally Radioactive Materials (NORM) from the three natural radioactive series and Potassium. The sludge usually returned to the environment and could cause a serious hazard. The aim of the present work is to investigate the radioactive Radon gas (222Rn) concentration, which reflects the present of NORM concentration in the sludge waste produced from crude oil refinery. The selected samples of oil sludge, had been grinded and dried then a passive method for measuring radon concentration performed using solid State Nuclear Detectors (SSNTD) technique. Two detectors were used in this work; CR39 and L115-II. Samples of sludge were collected, from different locations and from each location three samples collected in different depth. The arithmetic average radon concentration was 26089 Bq/m3, with maximum131618 Bq/m3 and minimum 2523 Bq/m3.
