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XOQDOQ Overview

XOQDOQ is a computer code used to evaluate routine or anticipated, intermittent releases of radionuclides at nuclear power plants. These assessments are required by 10 CFR Part 50 and 10 CFR Part 100. Relative atmospheric dispersion (X/Q) and deposition factors (D/Q) are calculated for 22 specific distances out to 50 miles from the site in each directional sector. The user can also select specific points of interest and evaluate releases of material to the atmosphere and predict resulting normalized concentrations and deposition amounts over periods of time.


The model is based on a straight-line Gaussian model. XOQDOQ accounts for variation in the location of release points, additional plume dispersion due to building wakes, plume depletion via dry deposition and radioactive decay, and adjustments to consider non-straight trajectories.