Explaining public acceptance of small modular reactors in Thailand: Planned behavior, innovation attributes, moral norms, risk–benefit, and knowledge sharing

Abstract

Small modular reactors (SMRs) are increasingly discussed as a low-carbon option to strengthen energy security, yet their deployment depends on public acceptance. Empirical evidence on SMR acceptance remains limited, particularly in developing countries such as Thailand, and prior studies have rarely provided a theory-integrated test that combines behavioral, innovation, moral–normative, and risk–benefit mechanisms within a single explanatory framework. Addressing this gap, this study examines determinants of SMR acceptance in Thailand by developing and testing an integrated framework combining Diffusion of Innovation (DOI), the Theory of Planned Behavior (TPB), and the Norm Activation Model (NAM), together with perceived risk–benefit appraisals and knowledge sharing. Data were collected through an online questionnaire survey during November–December 2025. Respondents were screened to include individuals with prior awareness of SMRs, yielding 428 valid cases. The proposed model was assessed using partial least squares structural equation modeling (PLS-SEM). Results indicate that behavioral intention is the most proximal predictor of SMR acceptance and is shaped by attitude, subjective norm, perceived behavioral control, and personal norm. Innovation perceptions—especially observability—strengthen attitudes, while knowledge sharing substantially enhances perceived behavioral control. Perceived risk and perceived benefit are significant predictors of subjective norm, suggesting that risk–benefit narratives may operate through socially shared discourse and normative signaling within reference groups. The findings provide a policy-relevant explanation of SMR acceptance and suggest that stakeholder engagement should prioritize institutionalized knowledge infrastructures, evidence transparency and independent validation, and participatory mechanisms that improve public understanding and support informed decision-making for low-carbon energy transitions.