The European Pressurized Water Reactor Project (EPR) is based on an innovative design concept for a new type of pressurized water reactor. The development of this concept will be carried out by a consortium of international partners and customers based in Germany and France. During the development of the EPR large amounts of up-to-date engineering data (i.e. CAD data, planning documentation) have to be made available to all project partners for presentation and development. This paper describes the web-based tool Virtual Web Plant (VWP), a tool to integrate 3D models from various CAD plant design tools and to display them interactively. The tool receives the data through the Internet. We describe the special advantages of an object-oriented database for the storage of the graphical data are shown. Through the application of object-oriented databases, it is possible to define various views of the logical plant structure, for example. The user is hereby able to navigate easily through both the plant structure and the project documentation. The work presented in this paper is part of a Virtual Reality Research Project of the Heinz Nixdorf Institute and the Siemens AG KWU.