[en] This engineering analysis documents the results of a study to establish the allowable vacuum to prevent bottom uplift or buckling of steel liner during waste retrieval activities of single-shell tanks (SSTs) located on the Hanford Site near Richland, Washington. Current OSD-T-151-00013 (2002) limits on SST vacuum are too restrictive as the tanks approach empty during waste retrieval. A summary of the SST liner design parameters is provided in Table 1. Buckling or uplift of the dished bottom and cylindrical sidewall portions of the carbon steel liners are investigated for each of the twelve SST tank farms taking into account predicted losses in liner wall thickness due to general corrosion as given in the Appendix. The additional vacuum in excess of the self-weight and residual waste to cause uplift of flat bottom tanks (A and AX) or buckling of the dished bottom tanks (all other SSTs) is very small except for the 200-Series SSTs. In general, the buckling of the steel liner due to internal vacuum is elastic and the bottom portion of the liner controls the allowable vacuum when the tank is empty provided that the general corrosion of the sidewall portion of the liner is not significantly greater than that of the bottom portion of the liner. This is not always the case if the predicted high corrosion loss for the liner sidewall of some SSTs is realized. This document provides a documented basis for the allowable vacuum to prevent bottom uplift or buckling of single-shell tank steel liners during waste retrieval activities