Computational Modeling of Radionuclide Migration in Saharan Aquifers After the French Nuclear Tests (1960–1966)

Abstract

NOUI Abderrahmane and GUESBAYA Zineb

Between 1960 and 1966, France conducted a series of atmospheric and underground nuclear tests in the Saharan regions of Reggane and In Ekker (Algeria), generating complex radiological phenomena whose long-term dynamics remain insufficiently quantified. Seventeen underground detonations introduced significant radionuclide inventories— principally Sr-90, Cs-137, and Pu-239—into fractured geological formations, creating persistent subsurface contamination pathways. This study develops a theoretical and computational assessment of radionuclide migration in deep and shallow aquifers, integrating hydrogeophysical modeling, radioactive decay kinetics, and transport equations under arid-zone conditions.

Model simulations calibrated with recent field measurements reveal radionuclide concentrations exceeding international radiological thresholds by up to one order of magnitude near test cavities. Approximately 40% of sampled wells within 50 km of Reggane exhibit anomalous Sr-90 activity, while Cs-137 signatures are detectable at distances reaching 200 km, implying long-range atmospheric deposition coupled with delayed infiltration. Theoretical dispersion models further indicate that Pu-239 may persist in confined aquifer systems for 104–105 years, posing substantial long-term risks.

Epidemiological datasets analyzed in parallel show statistically significant increases in thyroid cancers (+50%) and congenital anomalies (+30%) among populations chronically exposed to contaminated groundwater and agricultural products. These findings underscore the absence of systematic monitoring frameworks, uncertainties in historical yield and leakage parameters, and the lack of transparent radiological inventories.

The study emphasizes the need for long-term (10–15 years) integrative research, combining advanced computational modeling, high-resolution radiological mapping, and environmental forensics. Additionally, remediation strategies and sustained medical support must be implemented to mitigate the multi-decadal impacts of one of the most under- documented nuclear contamination events of the 20th century. International scientific cooperation and accountability remain crucial to address the persistent radiological and humanitarian consequences of these nuclear tests.

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