The National Fusion Collaboratory (NFC) project was created to advance scientific understanding and innovation in magnetic fusion research by enabling more efficient use of existing experimental facilities through more effective integration of experiment, theory, and modeling. To achieve this objective, NFC introduced the concept of "network services", which build on top of computational Grids, and provide Fusion codes, together with their maintenance and hardware resources as a service to the community. This mode of operation requires the development of new authorization and enforcement capabilities. In addition, the nature of Fusion experiments places strident quality of service requirements on codes run during the experimental cycle. In this paper, we describe Grid computing requirements of the Fusion community, and present our first experiments in meeting those requirements.