IAEA Workshop Introduces Novel Methods to Enhance Seismic Safety of Nuclear Installations

The IAEA is preparing a series of technical documents with input from a wide spectrum of consultants from the nuclear industry to further this support.

Earthquake experts and members of the nuclear community recently convened at the International Atomic Energy Agency (IAEA) in Vienna to explore innovative methods for improving the seismic safety of nuclear installations. The workshop, titled ‘Recent Advances in Seismic and Fault Displacement Hazard Assessment for Nuclear Installations,’ brought together over 120 participants from 56 countries to discuss new approaches in this critical field.

Given the frequency of major earthquakes worldwide and their potential impact on nuclear safety, such as the Fukushima Daiichi incident in 2011, the workshop emphasized the importance of advancing methodologies in seismic and fault displacement hazard assessments. These advancements are essential for enhancing the resilience and safety of nuclear installations against seismic events.

“This workshop is a diverse event, with experienced professionals sharing their specialized expertise with young professionals in various areas of site safety assessments including earthquake engineering, seismology, geology, and geophysics," said Anna Bradford, Director of the IAEA Division of Nuclear Installation Safety. She highlighted the importance of open and effective communication among participants to facilitate knowledge transfer.

The workshop participants learned about the IAEA's updated safety guide on Seismic Hazards in Site Evaluation for Nuclear Installations, which incorporates novel approaches in ground motion characterization, treatment of epistemic uncertainties, and probabilistic approaches for fault displacement hazard assessment. These updates are part of the IAEA’s ongoing efforts to support countries in applying these new methodologies practically. The IAEA is preparing a series of technical documents with input from a wide spectrum of consultants from the nuclear industry to further this support.

Key areas covered during the workshop included regulatory challenges in seismic safety review and assessment, particularly in light of lessons learned from the Fukushima Daiichi accident. Discussions also focused on ground motion and fault displacement modeling, with insights shared on national practices from Japan, the US, and Switzerland regarding site safety assessments and changes in regulatory requirements for natural hazards.

Professor Norman Abrahamson from the University of California, Berkeley, emphasized that significant changes are anticipated in vibratory ground motion estimates for nuclear installation sites over the next decade, facilitated by the non-ergodic approach which allows for more accurate ground motion predictions. He noted the importance of the workshop in introducing these advancements to the nuclear community.

The IAEA supports countries through its Site and External Events Design (SEED) Review missions, which assess site evaluations and design of nuclear installations to address challenges from earthquakes and other external events. The SEED mission provides an objective assessment of nuclear projects’ conformity with IAEA safety standards and guidance, including the updated IAEA Safety Guide SSG-9 (Rev.1) on Seismic Hazards in Site Evaluation of Nuclear Installations.

Quotes

Anna Bradford: “This workshop is a diverse event, with experienced professionals sharing their specialized expertise with young professionals in various areas of site safety assessments including earthquake engineering, seismology, geology, and geophysics."

Professor Norman Abrahamson: "Significant changes are expected in the vibratory ground motion estimates in nuclear installation sites in the next decade with the non-ergodic approach, which allows more accurate prediction of ground motion."

Key Takeaways

The workshop highlighted the importance of advancing seismic safety methodologies for nuclear installations.

The IAEA’s updated safety guide and ongoing support through SEED missions aim to enhance global nuclear safety standards.

Open communication and knowledge sharing among experts and young professionals are crucial for advancing the field.