Radiological risk assessment method for the interim storage of radioactive materials

Abstract

Safe storage of radioactive materials is based on three universal radiation protection principles. Justification, optimization and dose limits are applicable to the risk assessment, acknowledging the hazards in each procedure of delivery, usage, storage and disposal of radioactive materials. Failure Modes and Effects Analysis method (FMEA) is developed for the risk evaluation of common practices. In this work FMEA is exploited for the radiological risk assessment in practices using radioactive materials. In addition, the radiological hazard of fire is studied, in order to classify its severity for different examples of radioactive materials inventories. The severity of the hazard, the likelihood and the detectability of its occurrence are exploited for classifying the associated risk. Appropriate measures that should be taken for the emergency preparedness and response are taken into account in order to reduce the Risk Priority Number (RPN). Scenarios of external exposure, skin contamination and inhalation are investigated, in order to calculate the received doses, for workers and members of the public. The outcomes of the analysis indicate low or medium severity of the risks for most of the examined practices, especially under the implementation of the appropriate measures, like: controlled access of the facilities, records keeping for delivery, usage, storage and disposal of radioactive materials; presence of fire detectors and extinguishers; and removal of flammable materials from the vicinity of the radioactive materials.