Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPAPPENDIX CWMA 3 PRE-REMEDIATION DATA COLLECTIONC.1 BackgroundWaste Management Area 3 (WMA 3) is approximately 2.3 acres in size and contains the fourunderground waste storage tanks (8D-1, 8D-2, 8D-3, and 8D-4) and their associated supportingfacilities and infrastructure (see Figures C.1 and C.2 for maps).Descriptions of the various features of WMA 3 follow, and are taken from the Phase 1 DP,Section 3.1.2. A description of planned Phase 1 DP activities in WMA 3 can be found in SectionC.6.Waste Storage Tanks. The waste storage tanks were built to store the liquid high level wastegenerated during the NFS spent nuclear fuel reprocessing operations. The WVDP subsequentlymodified these tanks to support treatment and vitrification of the HLW. Modifications includedconstructing a fabricated steel truss system over tanks 8D-1 and 8D-2 to carry the weight ofsludge mobilization and transfer pumps and installation of treatment equipment in Tank 8D-1.Tanks 8D-1 and 8D-2 are identical in size and construction, with each tank housed within its owncylindrical concrete vault. Each tank is 27 feet high by 70 feet in diameter, with a storagecapacity of 750,000 gallons. The tanks were constructed with reinforced carbon steel plateranging in thickness from 0.4375 inch for the roofs and walls to 0.656 inch for the floors. Theroof of each tank is supported internally by 45 eight-inch diameter vertical pipe columns that reston a horizontal gridwork of wide flange beams and cross members in the bottom two feet of eachtank. Each tank rests on two six-inch-thick layers of perlite blocks that rest on a three inch layerof pea gravel. The tank, perlite blocks, and pea gravel are contained within a carbon steel panwhich rests on a three-inch layer of pea gravel that separates the pan from the floor of the vault.Each tank and its associated pan are housed within a cylindrical reinforced concrete vault that hasan outside diameter of 78.6 feet. The walls of each vault are 18 inches thick and extend nearly 36feet above the floor of the vaults. The floor of each vault is 27 inches thick, except under the six30-inch diameter vertical concrete columns that support the vault roof. These columns passupward from the floor of the vault through the tanks and are encased in steel pipes 48 inches inRev. 1 C-1