A technological innovation system in revival: Nuclear energy in Sweden

• Explores renewed interest in nuclear energy in Sweden through the TIS approach. • Shows how actors, institutional structure and technologies shape TIS revival. • Conceptualizes the TIS revival as an extension of the TIS lifecycle framework. • Argues for more attention to a non-linear dynamics of TIS development. • Highlights the importance of realignment and re-legitimation in shaping TIS revival. This paper explores the concept of Technological Innovation System (TIS) revival through the case of nuclear energy in Sweden—a sector that, after decades of stagnation and phase-out, is experiencing renewed political, institutional, and technological momentum. Drawing on the TIS lifecycle framework and guided by the research question, we investigate how TIS revival can be conceptualized within sustainability transitions literature. The complexity of the ongoing transformation of the nuclear energy sector is examined using data from desk research and semi-structured interviews. The study traces how expanding actor networks, institutional realignment, and the coexistence of mature and emerging technologies have contributed to reconfiguring the Swedish nuclear TIS, moving it beyond long-persisting decline and phase-out. The study contributes (1) conceptually, by developing the notion of TIS revival; (2) empirically, by demonstrating a non-linear development trajectory—from decline and phase-out to revival; and (3) by proposing a non-linear perspective on TIS development that accounts for diverse technological trajectories. It also contributes by unpacking how a contested socio-technical system can regain momentum under new contextual conditions.