HAZOP application for the nuclear power plants decommissioning projects

Highlights: • Identification of hazards during NPPs decommissioning activities. • Identification of potential hazard management strategies. • Identification of safety measures in order to prevent undue radiation exposures. • The adherence to the ALARA principles of time, distance and shielding. - Abstract: Decommissioning of nuclear facilities involves different types of activities, tools, equipment and systems. There is a potential for a wide range of radiological and industrial accidents during various stages of a decommissioning project creating risk for workers and the environment. The occurrence of accidents is possible due to many different operations involving movement and handling of large pieces of equipment and contaminated items. In addition, size reduction and decontamination processes are capable of producing hazards. One of the first steps in developing a safety assessment for decommissioning activities is the identification of hazards that can affect workers, members of the public and the environment during decommissioning activities, and then to identify engineered and administrative control measures to prevent, eliminate or mitigate the hazards and their consequences. Fault and hazard identification can be undertaken in several ways using a range of tools and techniques, including Hazard and Operability Study (HAZOP). The paper will mainly focus on the application of HAZOP technique for identification of the hazards raised due to dismantling and decontamination activities at the Ignalina NPP, as well as at feasibility study for the management of Bohunice V1 NPP primary circuit components.