February 4, 2005
Journal Article

Vadose Zone Modeling of Dispersed Waste Sites in the Framework of an Integrated Stochastic Environmental Transport and Impacts Assessment Code for the Hanford Site

Abstract

The System Assessment Capability (SAC) is the first total-system stochastic simulator to address inventory distribution, environmental release and transport, and impacts to human health and ecological, economic, and cultural resources from hundreds of radiological and chemical waste disposal sites for the entire Hanford Site in southeast Washington State. Flow and contaminant transport modeling in the vadose zone at 720 individual sites has been integrated into the SAC stochastic software framework using the Subsurface Transport Over Multiple Phases (STOMP) code, providing the means to define release to the regional aquifer to support the SAC groundwater transport model. Important features, events, and processes including remedial actions, time-variant natural infiltration rates, and high volume aqueous-phase discharges were addressed in the software and data. A data extraction program was developed to enable analysts to aggregate vadose zone release data across the hundreds of waste sites in various ways to develop an improved understanding of the system performance and uncertainty aspects.

Revised: February 21, 2005 | Published: February 4, 2005

Citation

Nichols W.E., G.V. Last, and C.T. Kincaid. 2005. Vadose Zone Modeling of Dispersed Waste Sites in the Framework of an Integrated Stochastic Environmental Transport and Impacts Assessment Code for the Hanford Site. Stochastic Environmental Research and Risk Assessment 19, no. 1:24-32. PNNL-SA-37069. doi:10.1007/s00477-004-0201-9