100-NR-2 Apatite Treatability Test: An Update on Barrier Performance

摘要

Following an evaluation of potential strontium-90 (90Sr) treatment technologies and their applicability under 100-NR-2 hydrogeologic conditions, the U.S. Department of Energy, Fluor Hanford, Inc. (now CH2M Hill Plateau Remediation Company), Pacific Northwest National Laboratory, and the Washington State Department of Ecology agreed that the long-term strategy for groundwater remediation at the 100-N Area should include apatite as the primary treatment technology. This evaluation indicated that the apatite permeable reactive barrier technology had the greatest promise for reducing 90Sr flux to the Columbia River at a reasonable cost. In June and July 2008, full-concentration, apatite solution injections were performed in support of the initial phase of barrier-emplacement operations for the 91-m (300-ft)-long apatite PRB section. Injection performance and 1-year of monitoring data were described in a previous report. This report updates the performance monitoring of the permeable reactive barrier (PRB) with an additional year of monitoring results, providing 2 years of data following initial treatment with full-concentration, phosphate amendment solutions.