A particle tracking numerical model was utilized to statistically evaluate near- and far-field impacts to a nuclear generating station’s intake basin.  Far-field particle tracking indicated which portions of the estuary provided potential detritus sources to the intake basin.  The near-field particle tracking analysis evaluated the migration of detritus cleaned from the intake screens and dumped back into the estuary.  Both the near- and far-field analysis show the utility of the particle tracking model for evaluating detritus movement in the upper Delaware Bay estuary.

The far-field modeling results indicated that detritus sources are restricted to a region extending approximately eight (8) miles south of the nuclear generating station.  This distance corresponds to one tidal excursion south of the intake basin, based on the estuarine conditions in the spring/summer of 1995.  The freshwater inflow, largely due to the Delaware and Schuylkill Rivers, provides a net background estuarine flow toward the Atlantic Ocean.  This particle tracking model also indicated that a high percentage of detritus entering the generating station’s intake basin is derived from particles traveling along the eastern portion of the estuary.  The pathway into the intake basin typically showed particles migrating from the north side of the intake basin, past the basin during the ebb tide cycle, and entering the basin from the south during the following flood cycle.  The details of particle pathways will aid in the design of effective mitigation measures needed to reduce or eliminate the detritus problem.