Numerical Modeling of 90Sr and 137Cs Transport from a Spill in the B-Cell of the 324 Building, Hanford Site 300 Area
[摘要] To characterize the extent of contamination under the 324 Building, a pit was excavated on the north side of the building in 2010 by Washington Closure Hanford LLC (WCH). Horizontal closed-end steel access pipes were installed under the foundation of the building from this pit and were used for measuring temperatures and exposure rates under the B-Cell. The deployed sensors measured elevated temperatures of up to 61 C (142 F) and exposure rates of up to 8,900 R/hr. WCH suspended deactivation of the facility because it recognized that building safety systems and additional characterization data might be needed for remediation of the contaminated material. The characterization work included additional field sampling, laboratory measurements, and numerical flow and transport modeling. Laboratory measurements of sediment physical, hydraulic, and geochemical properties were performed by Pacific Northwest National Laboratory (PNNL) and others. Geochemical modeling and subsurface flow and transport modeling also were performed by PNNL to evaluate the possible extent of contamination in the unsaturated sand and gravel sediments underlying the building. Historical records suggest that the concentrated 137Cs- and 90Sr-bearing liquid wastes that were spilled in B-Cell were likely from a glass-waste repository testing program associated with the Federal Republic of Germany (FRG). Incomplete estimates of the aqueous chemical composition (no anion data provided) of the FRG waste solutions were entered into a geochemical speciation model and were charge balanced with nitrate to estimate waste composition. Additional geochemical modeling was performed to evaluate reactions of the waste stream with the concrete foundation of the building prior to the stream entering the subsurface.
[发布日期] 2012-03-19 [发布机构]
[效力级别] [学科分类] 材料科学（综合）
[关键词] ANIONS;CHEMICAL COMPOSITION;CLOSURES;CONCRETES;CONTAMINATION;DEACTIVATION;LIQUID WASTES;NITRATES;SAFETY;SAMPLING;SAND;SEDIMENTS;SENSORS;SIMULATION;STEELS;TESTING;TRANSPORT;WASTES [时效性]
