The IAEA’s Nuclear Harmonization and Standardization Initiative
In recent years, there has been growing interest in the global deployment of standardized advanced nuclear reactors, including small modular reactors. This trend has been accompanied by an increase in regulatory reviews and has placed greater demands on regulatory resources. At the same time, the current differences in regulatory and industrial approaches among countries have made the standardization of reactor designs across national borders challenging.
To address these challenges, the IAEA launched the Nuclear Harmonization and Standardization Initiative (NHSI) in 2022 to support the effective global deployment of safe and secure advanced nuclear reactors. The initiative is structured in two interfacing tracks: one for technology holders and operators (the Industry Track) and one for regulators (the Regulatory Track).
The NHSI Industry Track aims to develop tools and industrial approaches for the effective large scale deployment of advanced reactors, with particular emphasis on small modular reactors. In parallel, the NHSI Regulatory Track aims to develop a global framework for the regulatory review
of advanced reactors, also with particular attention to small modular reactors. The framework is intended to outline common regulatory requirements and establish a shared understanding of how to meet them; to enhance national reviews by enabling regulatory bodies to take maximum advantage of international efforts and the work of other regulatory bodies; and to enable the sharing of regulatory resources and the implementation of joint reviews, without introducing additional regulatory steps or increasing the duration of national licensing processes.
To develop this global framework, a clear, staged approach was envisaged for the NHSI Regulatory Track, with three distinct phases of work. The first phase, completed in 2024, focused on the development of processes and tools to promote cooperation in regulatory reviews and increase
alignment in review outcomes. It is envisaged that the second phase will focus on implementing the processes and tools developed during the first phase, as well as on gathering feedback to improve cooperation processes and to map the regulatory differences among Member States. The final
phase is planned to focus on assembling the elements necessary to establish the global framework for regulatory reviews based on the feedback collected, in addition to building on the identified regulatory requirement commonalities and launching targeted efforts to address the differences.
This publication is primarily intended for regulatory bodies and technical support organizations, but it is also relevant to industry stakeholders, such as vendors that support licensees, because it provides insights into the information sharing process that can enhance communication and collaboration. between regulatory bodies and the industry. By fostering a more transparent and consistent basis for the global review of advanced reactor designs, the framework supports the early identification and resolution of potential regulatory issues, thereby reducing risks and facilitating the approval process during subsequent national licensing stages.