Veronique Royer and Didier Jacqueman of the Atomic Energy Agency have stressed the need to strengthen and better coordinate nuclear safety research around the world.
The expected increase in global nuclear energy capacity in the coming years will require a concerted effort to address the nuclear safety challenges that may arise from the introduction of new designs, including a wide range of small modular reactor (SMR) designs. This need is further amplified by the recent closure of critical nuclear safety research infrastructure, such as experimental reactors, reducing available expertise and capacity. Without globally coordinated action, the gap between research needs and available capacity will further widen, challenging the ability to ensure safety in both existing and next-generation nuclear reactors.
To address this challenge, the Nuclear Energy Agency (NEA) has developed comprehensive and detailed guidance for international nuclear safety research by identifying top priorities and outlining strategic direction in this area. The Strategic Roadmap for Nuclear Reactor Safety Research (NEA, 2025) focuses specifically on nuclear reactor safety and presents a comprehensive assessment of existing technical capacity, research infrastructure needs, stakeholder engagement, and funding challenges. It outlines the technology areas that require the most immediate attention and provides recommendations to support safety research with input from governments, regulators, industry, and international organizations.
This roadmap, whose key points are also outlined in a brochure (NEA, 2025a), can be used by policymakers and other key stakeholders to effectively support research initiatives to safely accelerate the deployment of new nuclear facilities, including in countries without previous nuclear power programs. This new development will be influenced by several topics across different reactor types and applications, including advanced manufacturing (such as 3D printing), cutting-edge modeling and simulation, and artificial intelligence (AI) and machine learning. The cross-cutting nature of these topics highlights the importance of collaborative research to optimize resources and accelerate results. Importantly, their safety implications must be well understood before they can be incorporated into plant operations.
Coordinated research is also needed to support innovative ways to use nuclear energy for purposes other than electricity production, such as industrial heat, hydrogen production, seawater desalination, and district heating. Safety aspects of these new applications must be addressed early in the technology development and regulatory process. Again, strong collaboration between governments, industry, regulators and their technical support organizations (TSOs) is required to deliver the needed research by leveraging global expertise, optimizing the use of resources, and supporting harmonized regulatory decisions, even when national regulatory frameworks differ. Meanwhile, the timely development and introduction of new nuclear technologies and applications requires industry to quickly address emerging safety issues while protecting proprietary rights and supporting timely regulatory review.
The special facilities and know-how required for nuclear safety research are often costly for each country to maintain, highlighting the importance of international cooperation. NEA has been conducting joint nuclear safety research projects since the 1960s, demonstrating the value of such coordinated efforts. These projects include experimental research, code development and validation, infrastructure support, training and knowledge management. Further expansion of the global research network will accelerate safety research and facilitate the licensing and deployment of nuclear reactors.
Due to the wide variety of reactor technologies in use and development, no country can afford to conduct safety studies across all designs. It is therefore essential to set clear priorities, both at the national level and through international agreements. These priorities must be determined by a variety of factors, including national needs, time frames for resolving safety gaps, infrastructure availability, funding, workforce skills, and technology commercialization readiness. We need a balanced approach that integrates national interests and international cooperation.
NEA’s Strategic Roadmap for Nuclear Safety Research outlines key research needs and challenges in the key areas described below.
General recommendations
Countries should strengthen cooperation to secure funding for: developing and maintaining research infrastructure and ensuring the availability of facilities essential for advanced nuclear safety research; Research that can independently verify the safety claims of reactor designers and operators. Research conducted during the early stages of reactor concept development to support the definition of preliminary safety requirements and facilitate capacity building within the nuclear safety community. Active industry involvement is important to ensure that real-world experiences are captured.
Fuel and cladding
As new nuclear technology focuses on higher burnup, high analysis low enriched uranium (HALEU) fuel and accident tolerant fuel (ATF), the following strategic actions are recommended:
Establish a collaborative program with industry support to build a library of fuels and cladding materials of general and cross-cutting interest, enabling meaningful experimental and modeling research across a variety of reactor technologies. Invest in advanced fuel testing infrastructure, including in-reactor testing under normal and non-normal conditions and commercial reactor testing using lead test fuel. These capabilities are essential for demonstrating safety margins under real-world operating conditions and validating performance claims for current and next-generation fuels and cladding. Advance research on Accelerated Fuel Qualification (AFQ) to accelerate the introduction of innovative fuels and cladding to the market while maintaining strict safety standards. Evaluate the applicability of existing modeling and simulation tools to new fuels and cladding materials and identify critical gaps. These tools are essential for predicting material behavior across a variety of operational and accident scenarios, and enhancing their predictive capabilities is essential to informing regulatory decision-making.
advanced materials
New nuclear technologies can be characterized by extreme temperatures, high radiation fluxes, and corrosive interactions, so the following is recommended:
Advanced materials, particularly those intended for molten salt reactor applications, will be further tested to establish a technical basis for assessing long-term safety and performance. NEA will establish an expert group to identify gaps in safety research, outline needed experimental capabilities, and develop a long-term strategic research plan. Intensified research needs to be carried out to advance modeling and simulation tools to predict the long-term behavior of materials in state-of-the-art nuclear reactors.
thermohydraulics
The safety of nuclear reactor systems depends on thermo-hydraulic analysis. To generate high-quality experimental data that supports code validation and uncertainty quantification, we recommend the following:
NEA is establishing a collaborative framework for large-scale experimental projects focused on advanced reactor concepts, including SMR and passive safety systems. Stakeholders will prioritize maintaining, modernizing, and expanding laboratory infrastructure, particularly that identified by the NEA Senior Expert Group on Safety Research (SESAR). Traditional thermal-hydraulic data will be stored, updated, and enriched with new data related to advanced reactors and SMRs. Stakeholders continue to benchmark computational tools, particularly computational fluid dynamics (CFD) codes, against high-resolution experimental data, with an emphasis on complex two-phase flows, passive systems, and accident-tolerant fuels.
serious accident
There is a need to demonstrate that serious accidents leading to the release of significant radioactive materials can be virtually eliminated, and to establish a technical basis for improving accident management strategies. Therefore, we recommend the following:
Comprehensive, risk-informed analyzes of advanced reactor designs will be conducted and shared internationally to identify and characterize credible accident scenarios that may challenge containment integrity and radioactive release barriers. NEA organizes a global collaborative framework to coordinate experimental projects, support code development and validation, provide training, and preserve critical data for long-term use. The parties are supporting both the modernization of existing facilities and the development of new experimental capabilities in a collaborative framework tailored to advanced reactor design and system safety demonstration. Pre-deployment testing of advanced fuels, cladding, and materials includes dedicated severe accident experiments that enable more accurate modeling of core degradation, fission product behavior, and source term estimation.
Long-term and flexible operation
Extending the operating life of existing nuclear facilities is an important part of efforts to make the energy grid more flexible. Therefore, we recommend the following:
The international collaboration builds on the NEA SMILE project, which collects and studies aging materials from operating and decommissioned plants, expanding the global knowledge base on long-term degradation mechanisms. Data-driven and realistic degradation models are developed to support risk-based decision-making throughout the useful life of nuclear components. Research on the safety implications of flexible operations is expanding.
New disruptive methods and technologies
Innovative technologies (such as AI and digital twins) and methodologies (such as 3D printing and cybersecurity measures) can help ensure nuclear safety, but they also require a deep understanding of the risks. We recommend the following:
NEA convenes a group of experts to define technical requirements for the safe integration of disruptive technologies and methods to guide the nuclear sector in proactively managing potential safety impacts. Stakeholders will invest in developing high-quality, structured, and secure datasets that are essential for training and validating AI and machine learning models, while incorporating strong security and data integrity protocols.
References
NEA (2025), Strategic Roadmap for Reactor Safety Research, OECD Publishing, Paris NEA (2025a), “Reactor Safety Research: Enabling Safe Deployment”, OECD Publishing, Paris.
This article will also be published in the quarterly magazine issue 25.
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