This publication provides a summary of the INPRO collaborative project on synergistic nuclear energy regional group interactions evaluated for sustainability. Benefits of nuclear technology innovation can be amplified through co-operation among countries in the nuclear fuel cycle. Nuclear energy sustainability can be enhanced, not only for technology holders but also for a variety of technology users, including those who do not pursue innovations in their home countries. If one partner in a synergistic collaboration is achieving enhanced sustainability, then the other partner(s) may achieve similar enhancement through collaboration without the requisite large national investments in technology, R&D and related infrastructure development. Within the publication, 28 case studies have been conducted by Member States to identify and evaluate mutually beneficial patterns of co-operation in the nuclear fuel cycle and the driving forces and impediments involved in such co-operation.