Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPAPPENDIX HWMA 9 PRE-REMEDIATION DATA COLLECTIONH.1 BackgroundThe Waste Management Area 9 (WMA 9) is approximately 12 acres in size and contains theDrum Cell, Subcontractor Maintenance Area, and NDA Trench Soil Container Area (see FiguresH.1 and H.2 for maps). The descriptions below are taken from the Phase 1 DP, Section 3.1.2.Drum Cell. The Drum Cell was built in 1987 to store radioactive waste solidified in cement andpackaged in square 71-gallon drums. It is a pre-engineered metal building 375 feet long, 60 feetwide, and 26 feet high. The facility consists of a base pad, concrete shield walls, remote wastehandling equipment, container storage areas, and a control room within the weather structure. Thebase pad consists of concrete blocks set on a layer of compacted crushed stone, underlain bygeotextile fabric and compacted clay. Concrete curbs to support the drum stacks lie on top of thebase pad. All of the drums stored in the Drum Cell were removed in 2007 and disposed of atoffsite LLW disposal facilities. The Drum Cell will be removed during Phase 1 of the proposeddecommissioning.Subcontractor Maintenance Area. The Subcontractor Maintenance Area (also known as theContractor Vehicle Hardstand) is a compacted gravel pad measuring approximately 20 feet by 30feet located in the northwest corner of WMA 9. Prior to 1991, it was used by constructionsubcontractors to clean asphalt paving equipment with diesel fuel. In November 1991, the areawas remediated by removing the upper six inches of soil and replacing it with clean gravel. Theremoved soil was tested for Toxicity Characteristic Leaching Procedure parameters and found tobe nonhazardous solid waste. Since 1991, the area has been used as a staging area for heavyequipment and construction materials (stone, gravel). The gravel pad will be removed duringPhase 1 of the proposed decommissioning.NDA Trench Soil Container Area. The NDA Trench Soil Container Area (comprising the NDARoll-Off Hardstand and the Empty Waste Container Hardstand) is a gravel pad storage arealocated on the north side of WMA 9. It was used to store roll-off containers containing soilexcavated during the installation of the NDA Interceptor Trench (located in WMA 7), which wasRev. 1 H-1