The purpose of this paper is to describe the development and implementation phases of online graduate nuclear engineering courses that are part of the Graduate Nuclear Engineering Certificate program at Virginia Tech. Virginia Tech restarted its nuclear engineering program in the Fall of 2007 with 60 students, and by 2009, the enrollment had grown to three times its initial size. In this paper, we present the innovative ways we employed to differentiate the program from other programs nationwide. Starting in 2009, with education grants from the Nuclear Regulatory Commission (NRC), we began transforming the distance courses from video conferencing to an online format that uses asynchronous and synchronous technologies. We used design principles drawn from research and theories in disciplines such as adult learning, cognitive science, motivation, and education. During these phases we worked closely with the distance learning institute at Virginia Tech which employs a structured life cycle methodology for online course development. We discuss the instructional design approaches used to provide a meaningful learning experience for adults, particularly non-traditional students. In addition we examined observational data to indicate instances for experiential learning.