Uncertainty and sensitivity analysis for gas and brine migration at the Waste Isolation Pilot Plant: Permeable shaft with panel seals

Abstract Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis, stepwise regression analysis and examination of scatter plots are used in conjunction with the BRAGFLO model to examine two-phase (i.e., gas and brine) flow at the Waste Isolation Pilot Plant (WIPP), which is being developed by the US Department of Energy as a disposal facility for transuranic waste. The following topics are investigated to develop insights on factors that are potentially important in establishing compliance with applicable regulations of the US Environmental Protection Agency (i.e., 40 CFR 191, Subpart B; 40 CFR 268): (1) gas production due to corrosion of steel; (2) gas production due to microbial degradation of cellulosics; and (3) gas migration through a sealed shaft to the Culebra Dolomite. Important variables identified in the analysis include initial brine saturation of the waste, stoichiometric terms for corrosion of steel and microbial degradation of cellulosics, and seal permeabilities.