Representatives from over twenty countries met in Vienna last month to share national experiences on the protection of nuclear installations against external hazards such as floods, fire, typhoons and earthquakes, and to hear from theI IAEA on the progress of existing activities in this field at the Annual Meeting of the Extrabudgetary Programme of the IAEA External Events Safety Section (EESS).
Sixty-seven representatives from 22 countries participated in the meeting held from 4 to 7 October 2022, where IAEA experts provided an update on activities underway to support countries in the protection of nuclear power reactors, research reactors and fuel cycle facilities against external hazards and events induced by human activities. Participants deliberated over a number of major challenges for regulators, operators and engineers in relation to external event safety in relation to small modular reactors (SMRs).
"Recent IAEA activities in the area of advanced and emerging nuclear technologies confirmed a growing need for unprecedented support to a large number of countries embarking on nuclear power programmes - especially on SMR projects - which focuses on the need for suitable grading of site selection, and design and safety assessment approaches which are tailored to the new technologies but still compliant with the IAEA Safety Requirements," said Anna Hajduk Bradford, Director of the IAEA Division of Nuclear Installation Safety, in her opening remarks at the meeting. "At the same time, we identified an important need for support to structured capacity building programmes in these subject-areas, especially for regulators."
During the Special Session on Optimization of Protection of Small Modular Reactors (SMRs) Against External Hazards as part of the meeting, experts from Turkey, Canada, Romania, and the IAEA stressed that the application of safety requirements should be proportionate to the radiation risk that the installation poses to population and environment. The case of SMRs deserves special attention.
"The most challenging hazard for SMRs is likely to be seismic. Because of the modular design of most SMRs and of the need to control their construction cost, it is expected that seismic testing by similarity methods will be even more useful and representative than for classical nuclear power plants," said Ioannis Politopoulos, Research Director at the French Committee of Atomic Energy (Commissariat à l'Energie Atomique, CEA) and Chair of the Special Session.
In addition, participants also discussed recent challenges posed by climate change-related natural events to nuclear installations all over the world, and the need to understand and react to the potential impact of these events on nuclear safety. Also on the agenda was a discussion on the potential consequences on the safety of nuclear power plants in areas of armed conflict.
The meeting participants were informed about ongoing analysis based on the database of external events reported to the IAEA over the past decade, which will be used to support countries in protecting their nuclear installations against hazards caused by external events.
"An analysis of external events in recent years shows us that the most reported incidents are related to rain or flooding," said Paolo Contri, Head of the EESS. "Most reported events are also related to so-called combined events: for example, a dam breach as a result of flooding, or the loss of electricity accompanied by extreme weather. Such events will become more common as a result of climate change."
Among the accomplishments presented at the meeting were the External Event Notification System, a system that will alert the IAEA of such events that could potentially affect nuclear installation sites, which was launched on the margins of the recent IAEA General Conference.
The roadmap for future actions includes proposals such as the development of new training manuals on sustainable safety for new installations such as SMRs, a greater focus on capacity building for regulators in countries embarking on nuclear power programmes, and the development of guidance on siting and assessment of nuclear waste repositories in relation to external events.
What are external events?
External events include natural disasters and events induced by human activities, such as plane crashes, which can wreak havoc on the environments in which they occur. When such events take place in an area where nuclear installations exist, the damage can become even more wide-ranging. The IAEA External Events Safety Section supports countries to help identify, evaluate, and mitigate these potential threats to nuclear installations.
The IAEA supports countries in five thematical areas relating to safety in the face of external events: siting, design, safety assessment, component qualification and capacity building. It provides support to countries specifically in site selection for nuclear installations and in assessment and evaluation of the safety of design of nuclear installations against external hazards.
Support includes safety review missions on nuclear installations conducted by the Site and External Events Design Review Service (SEED), the development of capacity building in this field, and the creation of related safety guides and technical documents.
The IAEA Safety Standards provide a robust framework of fundamental principles, requirements and guidance to ensure nuclear safety. They reflect an international consensus and serve as a global reference for protecting people and the environment from the harmful effects of ionizing radiation.
