Integrated latent risk of radiological damage under conflict situation-part I: Concept and approach

The set of protective arrangements implemented in response to uncontrolled radiological releases at nuclear installations greatly benefit from pre-existing provisions taken before the onset of the event during the so-called preparedness phase. Traditionally, emergency preparedness dispositions are implemented based on a single event occurrence at a specific location, i.e. event-oriented preparedness. However, such plans might prove inadequate in scenarios with an increase of accident risk affecting multiple nuclear installations. In these situations, the risk does not arise from an actual ongoing event at a specific installation, but rather from a degradation of the operational context conditions affecting wide areas of a territory hosting several nuclear facilities. In this case, there is no increase in sensitive risk due to an ongoing event but on the perceived, latent risk due a higher likelihood of accident arising from local conflicts or war scenario. Under such circumstances, event-oriented preparedness provisions might be insufficient to address the evolving of the new situation. This paper presents a methodology for the calculation of Emergency Planning Zone distances under conflict situation, based on the quantification of a novel risk figure of merit that integrates the different risk sources from different events and locations across a territory experiencing an overall degradation of the operational context conditions required for the safe functioning of nuclear and / radiological installations. The resulting conflict-situation related Emergency Planning Zones are not intended to replace the site-level existing zones, but rather to serve as an additional layer of defence built from an overall picture of the heightened latent risk affecting multiple nuclear installations. Aside from increasing the understanding of the risk distribution under the new challenging context conditions, the aggregated and quantitative nature of the new metrics provides a scientifically grounded basis criterion for decision-making regarding the allocation and extent of the protective provisions over the affected territory. This paper details the mathematical foundations of the new proposed risk-informed metrics. • Introduces a new framework to quantify latent radiological risk in conflict zones. • Defines risk-informed metrics integrating accident frequency and exposure likelihood. • Distinguishes sensitive vs latent risks for improved emergency preparedness. • Proposes conflict-specific EPZ distances based on aggregated territorial risk. • Establishes a top-down deterministic approach for bounding wartime scenarios.