Nuclear safety and security are absolute priorities for the European Union countries and this applies not only to nuclear power plants in operation but also to their decommissioning. The decommissioning process, like any other process with priority to safety and security, must be performed through a clear and achievable strategy. Also in order to minimize the costs and environmental impact during decommissioning it should be given considerations to the choice, the development and the implementation of the most adequate process of dismantling, treatment and storage of. In this paper the main projects in support to achieve safe and effective decommissioning process of the Units 1 to 4 at Kozloduy Nuclear Power Plant (NPP) are presented.