NEAR REAL TIME CHARACTERIZATION OF BNL STOCKPILED SOILS, ANOTHER ASTD SUCCESS STORY.
As of October 2001, approximately 7,000 yd{sup 3} of stockpiled soil, contaminated to varying degrees with radioactive materials and heavy metals, remained at Brookhaven National Laboratory (BNL) after the remediation of the BNL Chemical/Animal/Glass Pits disposal area. During the 1997 removal action, the more hazardous/radioactive materials were segregated, along with, chemical liquids and solids, animal carcasses, intact gas cylinders, and a large quantity of metal and glass debris. Nearly all of these materials have been disposed of. In order to ensure that all debris was removed and to characterize the large quantity of heterogeneous soil, BNL initiated an extended sorting, segregation, and characterization project, co-funded by the BNL Environmental Management Directorate and the DOE EM Office of Science and Technology Accelerated Site Technology Deployment (ASTD) program. Project objectives were to remove any non-conforming items, and to assure that mercury and radioactive contaminant levels were within acceptable limits for disposal as low-level radioactive waste. Sorting and segregation were conducted simultaneously. Large stockpiles, ranging from 150 to 1,200 yd{sup 3}, were subdivided into manageable 20 yd{sup 3} ''subpiles'' after powered vibratory screening. The 1/2 inch screen removed 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. Eight samples plus QA duplicates were collected from each subpile for chemical analysis, and a 1-Liter jar of material for gamma spectroscopy. A field lab equipped for chemical analysis and gamma spectroscopy was 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 Characteristic Leaching Procedure (TCLP) tests to verify that the soils were not RCRA hazardous. The modified (1/10th scale) TCLP tests minimized secondary (leachate) waste and maximized tumbler capacity and sample throughput. TCLP leachate analysis was accomplished using a Milestone Direct Mercury Analyzer (DMA-80). Gamma spectroscopy provided verification of previously measured Am-241, Cs-137, and Co-60 contamination levels. After analyses were completed and reviewed, the stockpiles were reconstructed 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/DMA analyses over an 18-week period. Reliable statistical verification was accomplished for more than 98% of the stockpile sub-piles; for most sub-piles, TCLP analyses were completed within two days. This enhanced level of confidence in soil characterization was accomplished at a cost far below equivalent baseline 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 to efficiency 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 sample collection rate, from three samples per 5 yd{sup 3} to two, resulted in further schedule acceleration. The resulting sample frequency, however, was still 22 times greater than the baseline frequency (one per 55 yd{sup 3}).
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Sponsoring Organization:
- DOE/SC (US)
- DOE Contract Number:
- AC02-98CH10886
- OSTI ID:
- 812681
- Report Number(s):
- BNL-71435-2003-CP; R&D Project: 86606; 820101000; TRN: US0303472
- Resource Relation:
- Conference: WASTE MANAGEMENT 2003 SYMPSOIUM, TUCSON, AZ (US), 02/23/2003--02/27/2003; Other Information: PBD: 23 Feb 2003
- Country of Publication:
- United States
- Language:
- English
Similar Records
Sulfur polymer stabilization/solidification (SPSS) treatment of mixed waste mercury recovered from environmental restoration activities at BNL
Decommissioning and Environmental Cleanup of a Small Arms Training Facility - 13225