Chernobyl and the transformation of nuclear safety culture: Technological governance, risk, and expertise after 1986

The Chernobyl disaster of 26 April 1986 remains one of the most significant technological accidents of the twentieth century and a defining event in the history of science and technology. While early interpretations of the accident focused primarily on reactor design deficiencies and operator actions, subsequent investigations demonstrated that its origins were rooted in a broader interaction of technological, organizational, and institutional factors. This article examines the Chernobyl disaster as a turning point in the evolution of nuclear safety culture and technological governance. Particular attention is devoted to the role of Soviet modernization policies, the development of the RBMK reactor programme, organizational culture within the Soviet nuclear industry, and the management of technical knowledge before and after the accident. The study employs methods of historical analysis, historiographical review, comparative analysis, and socio-technical systems analysis. It is based on international scientific literature, reports of the International Atomic Energy Agency, publications of the Chernobyl Forum, and recent studies in the history of technology, risk governance, and nuclear safety. The article analyses the technical and institutional origins of the disaster, the subsequent reassessment of nuclear risk, the crisis of technological expertise revealed by the accident, and the emergence of the concept of safety culture as a new framework for understanding technological reliability. The findings demonstrate that Chernobyl cannot be adequately explained as the consequence of either technical failures or human errors alone. The disaster represented a systemic failure arising from interactions among reactor design characteristics, organizational practices, institutional constraints, and deficiencies in the circulation of safety-related information. The study shows that the accident fundamentally transformed international approaches to technological risk, encouraged the development of safety culture as a key principle of nuclear governance, and stimulated new forms of international cooperation in the fields of nuclear safety, emergency preparedness, and regulatory oversight. The modernization of RBMK reactors after 1986 further illustrates how technological systems evolve through processes of institutional learning and adaptation. The article argues that the historical significance of Chernobyl extends far beyond the nuclear sector. The lessons derived from the disaster contributed to broader changes in the governance of complex technologies and remain relevant to contemporary discussions concerning sustainable technological development, risk management, and institutional resilience. Particular relevance is identified in relation to the United Nations Sustainable Development Goals associated with public health, sustainable energy, resilient infrastructure, and effective institutions. From the perspective of the history of science and technology, Chernobyl represents a crucial case study demonstrating how major technological accidents can reshape scientific knowledge, organizational practices, and international approaches to technological governance.