OCCUPATIONAL OVEREXPOSURE RISK PROBABILITY OF GAMMA INDUSTRIAL IRRADIATOR. PROBABILISTIC SAFETY ASSESSMENT STUDY

Occupational overexposure risk probability in gamma industrial irradiators was estimated using probabilistic safety assessment technique to ensure that the occupational radiation protection system meets the current safety requirements during different operations in all the phases of irradiator life cycle. even though there were adequate safety interlocks, the overexposure risk may be initiated upon entering the irradiation room, during normal/maintenance operations, while the water pool level is below its safe level or source fails to be lowered in its storage area due to malfunction and/or human errors. event tree and fault tree analysis is used to estimate failure frequency of initiation events related safety systems. although the estimated overexposure risk considered as low risk due to radiation protection several barriers exist in irradiator design inappropriate human performance, which is a critical contributing factor in risk estimation of such initiation events, may cause occupational overexposure risk.