Photon and Neutron sources are producing more and more petabytes of scientific data each year. At the same time scientific publishing is evolving to make scientific data part of publications. The Photon and Neutron Open Science Cloud (PaNOSC project is an EU financed project to provide scientific data management for enabling Open Science. Data will be managed according to the FAIR principles. This means data will be curated and made available under an Open Data policy, findable, interoperable and reusable. This paper will describe how the European photon and neutron sources on the ESFRI roadmap envision PaNOSC as part of the European Open Science Cloud. The paper will present the objectives of the project on the issues of data policy, metadata, data curation, long term archiving and data sharing in the context of the latest developments in these areas.