Abstract
This study was conducted primarily to survey aircraft and heavy machinery at 30 locations within Khartoum State using handheld radiation survey meters to detect and identify any radiation sources that might be present and to estimate radiation dose levels. The survey has resulted in detection of 16 sealed sources of 90Sr and one of 226Ra in aircraft scrap. Of course, 90Sr sources are used in military aircraft as temperature sensors while 226Ra is used for indicating fuel levels. These sources were found intact without spreading radioactivity contamination; however, none was detected in heavy machine scrap. The levels of radiation dose measured at 0.1m from the source fall within the range of 25.1–40.2μSv/h with an average value of 33.52±4.06μSv/h. These orphan sources have been separated from the scrap, tested for possible leakage, conditioned and stored in waste management facility. The result of this study has revealed without doubt that the scrap constitute a serious source of public exposure and highlights the importance of legislation making radiation monitoring of scrap in the country mandatory before it is sold to metal industry for reprocessing.
► Sealed radioactive sources (90Sr and 226Ra) were detected in aircraft scrap. ► No source was detected in heavy machine scrap. ► Radiation dose measured at 0.1m from the source can be used to estimate exposure to public. ► Monitoring of scrap was found to be useful for protection (from orphan sources).