Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPdiameter that are welded to the top and bottom of each tank. The columns are locatedapproximately 16 feet from the center of the tank. The floor of each vault is underlain by a fourfeet thick bed of gravel. The concrete vault roof is two feet thick and is supported by the sixconcrete columns. The top of the vaults are six to eight feet below grade. Despite their robustconstruction, the tank vaults have not proven to be watertight. Groundwater seeps into both vaultsand has to be regularly pumped out.Tanks 8D-3 and 8D-4 are identical in size and construction, and both are housed within a singlereinforced concrete vault. Each tank is 12 feet in diameter and 15.67 feet high, with a nominalvolume of 15,000 gallons. The shell of each tank is 0.313 to 0.375 inch thick; both the tanks andtheir associated piping were constructed from 304L stainless steel. The concrete vault that housesthe tanks is approximately 32-feet long, 19-feet wide, and 25-feet tall. The walls, floor, and roofof the vault are 21-inches thick. The bottom of the vault is lined with stainless steel to a height of18 inches above the floor. The floor contains a stainless-steel-lined sump. The top of the vault issix to eight feet below grade.High-Level Waste Transfer Trench. The HLW transfer trench is a long concrete vault containingpiping that conveyed waste between the Waste Tank Farm and the Vitrification Facility.Approximately 500 feet long, the trench extends from the Tank 8D-3/Tank 8D-4 vault along thenorth side of Tank 8D-1 and Tank 8D-2 at ground level, before turning to the southwest andentering the north side of the Vitrification Facility. It is six to 20 feet wide and its height rangesfrom six to nine feet. The trench was constructed with reinforced concrete walls and floors, withpre-cast concrete covers. Stainless steel-lined concrete pump pits that house the upper sections ofHLW transfer pumps are located on top of each of the tank vaults. The walls and floors of thepump pits are reinforced concrete, with pre-cast concrete covers forming the roof. There are sixpiping runs in the trench, two of which are unused spares, comprising approximately 3000 linearfeet of double-walled stainless steel pipe. The trench also contains associated valves and jumpers.The pump pits each contain the upper part of the HLW transfer pump and flow monitoringequipment. Pump Pit 8Q-2 over Tank 8D-2 also contains grinding equipment used to size reducezeolite.Permanent Ventilation System Building. The Permanent Ventilation System Building is locatedapproximately 50 feet north of Tank 8D-2. This steel framed and sided building is 40 feet wide,75 feet long, and 16 feet tall and is attached to a 12 inch thick concrete floor slab supported byRev. 1 C-2