Scoping Calculations of Tank 48 Vapor Space Mixing

Lee, S

Savannah River Site (S.C.)

关键词: Safety Engineering;    Radioactive Waste Facilities;    Calculation Methods;    Vapors;    Benzene;   

DOI  :  10.2172/890200
RP-ID  :  WSRC-TR-2005-00470
RP-ID  :  DE-AC09-96SR18500
RP-ID  :  890200

美国|英语

来源: UNT Digital Library

【 摘 要 】

Scoping calculations to address the mixing behavior of benzene in the vapor space of Tank 48 and estimate maximum benzene concentrations have been completed. The analysis was focused on determining whether a detailed assessment using a computational fluid dynamics (CFD) model of the Tank 48 vapor space could support Safety Class calculations. The calculations included nominal boundary conditions for air inlet and exhaust flows, as well as benzene evolution from the tank liquid surface. Additional calculations included a reduced benzene evolution rate, reduced air inlet and exhaust flows, and a modified air inlet location. The calculations were based on prototypic tank geometry and nominal operating conditions as defined by the Closure Business Unit. The results showed that the vapor space was fairly well mixed and that benzene concentrations were relatively low for typical operating conditions. All the calculations addressing sensitivity issues such as differencing options, mesh density, and transient performance in the model demonstrated that the scoping model could capture the necessary phenomena without introducing nonphysical behavior because of the numerical discretization. Therefore, refining and upgrading the present scoping model is feasible for support of safety class calculations.