The development and commercial introduction of advanced nuclear reactor fuel is slowed by the long turnaround time required by the methodology’s cycle of in-core irradiation, cooling, shipping and post irradiation examination (PIE). PIE is complicated and costly due to the high activation of the irradiated fuel. During the development process, which can extend over several years, access to fuel cladding operating data is very limited. Incorporating a real-time, remote, fuel monitoring system into the fuel rod can provide critical information on such parameters as centerline fuel temperature, axial fuel pellet elongation and rod internal pressure that can enable fuel models to be adjusted in real time and accelerate the licensing approval process. By transmitting the information from the integral sensor through the cladding, penetrations into the fuel rod are avoided and the performance of the fuel is not compromised. Data on fuel performance is generated immediately on startup of the instrumented fuel rod and can continue throughout the life of the rod. This data can be used immediately to inform further fuel development activities and can also be used to target PIE activities to enhance their usefulness and reduce costs. This paper will describe the prototype sensor development, operation and results obtained during the irradiation program at the Massachusetts Institute of Technology Reactor (MITR).