As of October 2001, approximately 7,000 yd3 of stockpiled soil, contaminated to varying degrees withradioactive materials and heavy metals, remained at Brookhaven National Laboratory (BNL) after theremediation of the BNL Chemical/Animal/Glass Pits disposal area. During the 1997 removal action, themore hazardous/radioactive materials were segregated, along with, chemical liquids and solids, animalcarcasses, intact gas cylinders, and a large quantity of metal and glass debris. Nearly all of thesematerials have been disposed of. In order to ensure that all debris was removed and to characterize thelarge quantity of heterogeneous soil, BNL initiated an extended sorting, segregation, and characterizationproject, co-funded by the BNL Environmental Management Directorate and the DOE EM Office ofScience and Technology Accelerated Site Technology Deployment (ASTD) program. Project objectiveswere to remove any non-conforming items, and to assure that mercury and radioactive contaminant levelswere within acceptable limits for disposal as low-level radioactive waste.Sorting and segregation were conducted simultaneously. Large stockpiles, ranging from 150 to 1,200 yd3,were subdivided into manageable 20 yd3 “subpiles” after powered vibratory screening. The ? inch screenremoved gravel and almost all non-conforming items, which were separated for further characterization.Soil that passed through the screen was also visually inspected before being moved to a subpile. Eightsamples plus QA duplicates were collected from each subpile for chemical analysis, and a 1-Liter jar ofmaterial for gamma spectroscopy. A field lab equipped for chemical analysis and gamma spectroscopywas set up in a trailer close by the stockpile site. Chemical analysis included X-ray fluorescence (XRF)to screen for high (>260 ppm) total mercury concentrations, and modified Toxicity CharacteristicLeaching Procedure (TCLP) tests to verify that the soils were not RCRA hazardous. The modified (1/10thscale) TCLP tests minimized secondary (leachate) waste and maximized tumbler capacity and samplethroughput. TCLP leachate analysis was accomplished using a Milestone Direct Mercury Analyzer(DMA-80). Gamma spectroscopy provided verification of previously measured Am-241, Cs-137, andCo-60 contamination levels. After analyses were completed and reviewed, the stockpiles werereconstructed for later disposal as discrete entities within a disposal site profile.The ASTD field laboratory completed more than 2,500 analyses of total Hg (XRF) and TCLP/DMAanalyses over an 18-week period. Reliable statistical verification was accomplished for more than 98% ofthe stockpile sub-piles; for most sub-piles, TCLP analyses were completed within two days. Thisenhanced level of confidence in soil characterization was accomplished at a cost far below equivalentbaseline techniques. One of the most significant aspects of the project success was schedule acceleration.The original schedule projected activities extending from early April until September 30. Due toefficiency and reliability of the vibratory screening operation and cooperative, dry summer weather,stockpile reconstruction was completed in the third week of August. Reduction of the planned samplecollection rate, from three samples per 5 yd3 to two, resulted in further schedule acceleration. Theresulting sample frequency, however, was still 22 times greater than the baseline frequency (one per 55yd3).
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