The IAEA released a complementary methodology for assessing the safety vulnerabilities of nuclear power plants on 16 November 2011. Based on IAEA Safety Standards, the Methodology for Member States to Assess the Safety Vulnerabilities of Nuclear Power Plants against Site Specific Extreme Natural Hazards was developed and delivered to the IAEA's Member States as one of the methods to be used when carrying out national nuclear safety assessments. The methodology details the systematic analysis of the safety impact of extreme natural hazards (i.e. earthquakes, tsunamis, extreme weather) at a nuclear power plant and their possible effects.
As part of the IAEA's Action Plan on Nuclear Safety, the IAEA devised the methodology as part of its comprehensive program to learn lessons from the Fukushima Daiichi Nuclear Power Plant accident in Japan and to take concrete steps to improve global nuclear safety.
The methodology provides practical methods to assess whether structures, systems, components and operator actions are sufficiently resilient to be able to fulfil necessary safety functions when extreme events occur. This systematic approach provides Member States options that can enhance the plant's robustness.
The IAEA is in the process of extending its design review service to include modules for the peer review of national assessments that have been carried out by Member States. This service uses the Safety Requirements and Guides of the IAEA Safety Standards Series to focus on the design and safety assessment aspects of protection against extreme events, including defence in depth, safety margins, robustness, cliff edge effects, multiple failures, the prolonged loss of essential systems and recovery actions carried out by the plant operators.