Abstract:  Small modular reactors (SMRs) have been proposed as a way to decarbonise urban district heating. To be technically and economically viable, SMRs should be located close to existing district heating networks and thus near residents. This would likely raise questions about fairness of, for example, the distribution of risks and benefits, and the opportunities to participate in SMR site selection. This article examines the role of energy justice in the construction of the technoscientific promise of SMRs. Such a construction process entails institutionalisation of the promise in, for example, policies, legislation, regulation, and funding decisions, and its materialisation in R&D, prototype, and commercial projects. The article analyses how energy justice considerations are used in either building or undermining the two key pillars of a technoscientific promise—its legitimacy and credibility. To be considered legitimate, a promise must address a widely recognised and urgent societal problem, whereas for credibility, it must be perceived as viable in practice. The processes whereby legitimacy and credibility are constructed and deconstructed, to foster or undermine the institutionalisation and materialisation of the promise, have significant implications for justice and equity across time, space, and groups of society. Building on earlier research on just energy transitions, the SMR promises in Finnish cities are analysed from three analytically distinct yet overlapping perspectives: distributive, recognition, and procedural justice. The material consists of documents and news items on R&D, policymaking, and municipal SMR initiatives.

Keywords:  energy justice; legitimacy; nuclear energy; small modular reactors; technoscientific promises

Published:   3 September 2026

Issue:   Vol 14 (2026): The Politics of Resilient and Just Energy Transitions: Institutions and Critical Infrastructure (In Progress)