Assessment of Radioactive Material Disposal Practices and Radiation Exposure at a Medical Imaging Centre in Ibadan

This study assesses the management and disposal practices for radioactive medical waste at a nuclear medicine and radiology centre in Ibadan, Oyo State, South West Nigeria, evaluating compliance with the Nigerian Nuclear Regulatory Authority guidelines and potential radiation exposure risks to workers and the public. Medical imaging and nuclear medicine facilities generate radioactive waste including spent sealed sources, contaminated consumables, and short-lived radioisotope residuals that require controlled storage, decay management, and licensed disposal. Assessment was conducted through structured inspection using the Nigerian Nuclear Regulatory Authority medical waste inspection checklist, personnel dosimetry badge review for radiation workers, air dose rate measurements in controlled and supervised areas, and review of waste inventory and disposal records. Results show that sealed-source storage protocols are generally compliant with regulatory requirements, but disposal documentation for liquid radioactive waste including residual radiopharmaceuticals is incomplete, with no entries in the required disposal log for the preceding six months. Air dose rates in the controlled area meet NNRA limits, but one area adjacent to a storage cabinet exceeds the supervised area boundary dose rate. Three radiation workers show personal dose accumulation approaching the quarterly investigation level without formal investigation having been initiated. Waste storage labelling is partially compliant. The study identifies record-keeping and investigation level management as the primary compliance gaps. Recommendations include immediate restoration of waste disposal documentation and a staff refresher training on radiation protection procedures. Keywords: radioactive waste, radiation safety, nuclear medicine, NNRA, Ibadan.