Radiological impact assessment of hypothetical accident scenarios for an advanced PWR at the Sidi Boulbra candidate...

Radiological consequence assessment is essential for evaluating emergency preparedness at nuclear power sites, especially where plant-specific licensing data are not yet available. In Morocco, Sidi Boulbra was historically retained as a candidate nuclear power plant site; however, site-specific screening assessments of hypothetical large advanced pressurized water reactor (PWR) accident consequences using long-term local meteorology remain limited. Therefore, this study evaluates two hypothetical accident scenarios using a literature-based representative large advanced PWR source term applied to the Sidi Boulbra candidate site on the Moroccan Atlantic coast. The analysis was performed with the HotSpot Health Physics Code using seasonal meteorological conditions derived from 30-year National Oceanic and Atmospheric Administration Integrated Surface Database (NOAA-ISD) records covering 1995-2024. The study quantified projected plume-centerline total effective dose equivalent (TEDE) for the modeled release and plume-passage period, including the 50-year committed inhalation dose component, ground-surface deposition, organ-specific committed dose equivalent, and precipitation effects. Under dry conditions, Scenario AS1 produced a maximum TEDE of 6.10 × 10^-6 Sv, far below the supplementary comparison contour of 1.0 × 10^-2 Sv. Scenario AS2 was controlling, with a maximum dry TEDE of 1.10 × 10¹ Sv and deposition of 2.50 × 10⁷ kBq/m² near 0.10 km under winter Pasquill-Gifford (PG) class D conditions. With 1 mm/h precipitation, AS2 reached 1.50 × 10¹ Sv and 1.90 × 10⁸ kBq/m². Inhalation contributed 77-79% of AS2 TEDE, and the thyroid was critical due to radioiodine uptake. The results identify sector-based plume tracking, inhalation-dose reduction, thyroid protection, ground surveys, and contamination control as priorities for further emergency-planning assessment.