A containment and disposition strategy for tritium-contaminated groundwater at the Savannah River Site, South Carolina, United States

摘要

A containment and disposition water management strategy has been implemented at the Savannah River Site to minimize the discharge of tritiated groundwater from the Old Radioactive Waste Burial Ground to Fourmile Branch, a tributary of the Savannah River. This paper presents a general overview of the water management strategy, which includes a two-component (pond and irrigation) system, and a summary of operations and effectiveness for the first 3 yr of operations. Tritiated groundwater seep discharge was impounded by a dam and distributed via irrigation to a 22-ac (8.9-ha) upland forested area comprised of mixed pines (loblolly and slash) and hardwoods (primarily sweetgum and laurel oak). As of March 2004, the system has irrigated approximately 133.2 million L (35.2 million gal) and prevented approximately 1880 Ci of tritium from entering Fourmile Branch via forest evapotranspiration, as well as via pond storage and evaporation. Prior to installation of the containment and disposition strategy, tritium activity in Fourmile Branch downstream of the seep averaged approximately 500 pCi mL–1. Six months after installation, tritium activity averaged approximately 200 pCi mL–1 in Fourmile Branch. After 1 yr of operations, tritium activity averaged below 100 pCi mL–1 in Fourmile Branch, and a range of 100–200 pCi mL–1 tritium activity has been maintained as of March 2004. Complex hydrological factors and operational strategies influence remediation system success. Analyses may assist in developing groundwater management and remediation strategies for future projects at the Savannah River Site and other facilities located on similar landscapes.