Updated Drainable Interstitial Liquid Volume Estimates for 119 Single Shell Tanks (SST) Declared Stabilized

This document assesses the volume of drainable interstitial liquid (DIL) and pumpable liquid remaining in 119 single-shell tanks (SSTs) that were previously stabilized. Based on the methodology and assumptions presented, the DIL exceeded the stabilization criterion of less than 50,000 gal in two of the 119 SSTs. Tank 241-C-102 had an estimated DIL of 62,000 gal, and the estimated DIL for tank 241-BY-103 was 58,000 gal. In addition, tanks 241-BX-103, 241-T-102, and 241-T-112 appear to exceed the stabilization criterion of 5,000 gal supernatant. An assessment of the source of the supernatant in these tanks is beyond the scope of this document. The actual DIL and pumpable liquid remaining volumes for each tank may vary significantly from estimated volumes as a result of specific tank waste characteristics that are not currently measured or defined. Further refinement to the pumpable liquid and DIL volume estimates may be needed as additional tank waste information is obtained