Risk assessment on hazards for decommissioning safety of a nuclear facility

A decommissioning plan should be followed by a qualitative and quantitative safety assessment of it. The safety assessment of a decommissioning plan is applied to identify the potential (radiological and non-radiological) hazards and risks. Radiological and non-radiological hazards arise during decommissioning activities. The non-radiological or industrial hazards to which workers are subjected during a decommissioning and dismantling process may be greater than those experienced during an operational lifetime of a facility. Workers need to be protected by eliminating or reducing the radiological and non-radiological hazards that may arise during routine decommissioning activities and as well as during accidents. The risk assessment method was developed by using risk matrix and fuzzy inference logic, on the basis of the radiological and non-radiological hazards for a decommissioning safety of a nuclear facility. Fuzzy inference of radiological and non-radiological hazards performs a mapping from radiological and non-radiological hazards to risk matrix. Defuzzification of radiological and non-radiological hazards is the conversion of risk matrix and priorities to the maximum criterion method and the mean criterion method. In the end, a composite risk assessment methodology, to rank the risk level on radiological and non-radiological hazards of the decommissioning tasks and to prioritize on the risk level of the decommissioning tasks, by simultaneously combining radiological and non-radiological hazards, was developed.