In the wake of the March 2011 accident at the Fukushima Daiichi nuclear power plant, discussions about external natural hazards that are low in frequency but high in consequence have been ongoing. It has since been widely recognised that such hazards can lead to incidents that could challenge the safety of nuclear installations.
In this context, the NEA Working Group on External Events (WGEV) was established in 2014 in order to improve the understanding and treatment of external hazards that would support the continued safety performance of nuclear installations, as well as to improve the effectiveness of regulatory practices. The working group facilitates the exchange of information and experience on external hazards in NEA member countries.
The group held its biannual meeting on 1-5 March 2021 via video-conference. During the meeting, the group members held an extensive discussion on a draft benchmark report on external events hazard frequency and magnitude statistical modelling. This benchmark study intends to demonstrate and capture commendable practices in formulating and assessing the quantification of external event hazard initiating events when using statistical models.
The group members also finalised a technical report on the protection of nuclear installations against high winds and tornadoes and the identification of key issues regarding high wind and tornado hazard assessment. This report will be the basis for the workshop which will be organised in March 2022 in Korea, in conjunction with a separate workshop on addressing uncertainties in natural hazards. This new WGEV activity was launched at the March meeting.