The objective of this proposal is to investigate the feasibility and viability for existing Nuclear Power Plants (NPPs) to generate large amounts of hydrogen for supporting the decarbonisation goals of the EU- as the EU aims to be climate-neutral by 2050. Moreover, this feasibility study aims to prepare the realization of nuclear hydrogen generation projects in the short term (2025). Thereby, three major fields will be investigated: 1) Investigation of the technical, economic and operational feasibility 2) Development of configuration for a pilot project 3) Selection of pilot plant site(s) for implementation phase (2025) The superior goal of the NPHyCo project is to prepare a definite nuclear powered hydrogen cogeneration project with a short implementation horizon. This will be achieved by a comprehensive assessment of the technical feasibility and the commercial reasonability. The investigations will be focused on existing H2 generation technologies and existing and willing NPP to be able to implement a NPHyCo project within a 3-year time period after completion of this project. The NPHyCo project aims to gain knowledge concerning the coupling of NPP plants and newly built H2 plants. The project will propose an optimal degree of integration, to maximise mutual benefits, based on mutual integrity of both plants. The results will be summarized in practical decision matrixes, guidelines, and checklists. These results can be used by NPP operators, H2 generation EPCs and all other stakeholders, such as investors, safety authorities, notified bodies and H2 consumers for their decision-making processes.