Legal science is facing the relevant task of studying the existing legal forms and models of international scientific and technical cooperation on creation and utilization of global research infrastructure in the nuclear sphere, as well as determining their flaws and merits, capacity of implementation and adjustment to the “mega-science” projects in the Russian Federation. The key factors in determining legal aspects of creation and utilization of the global research infrastructure are the following: organizational-legal framework (establishment of an independent subject or usage of the already existing “umbrella” legal structures), and which legal tools are applied and to which law this activity is subordinated. The organizational-legal model of the international scientific and technical cooperation with existing intergovernmental organization of the framework type or legal entities, as well as by means of instituting of special subjects, can be schematically described as the four-level system. The advantage of using the umbrella-type models in nuclear sphere consists in availability of most of its tools and mechanisms, which require just the adjustment to the specific projects, and the possibility of implementation of a substantial number of projects. If there is a need for ensuring partnership on a shared basis, financial responsibilities, and the dependent on them management structure, the appropriate form is the creation of a special subject of project type. Based on the “legal environment”, the use of international intergovernmental organization implies certain immunities and privileges, removal from the jurisdiction of the accepting country, etc. It is important that in the modern conditions it is more difficult to subordinate the international intergovernmental organizations to the politically motivated unilateral restrictive measures (“sanctions”). Although, the use of the construct of legal entity can ensure better efficiency, flexibility, and managerial inexpensiveness of the process, especially as the also can qualify for the exceptions to national law. Most successful seems the development of a special organizational legal form mentioned in the draft Federal Law “On scientific, Scientific-and Technical, and Innovation Activity in the Russian Federation”, which would be an international research organization.