The U.S. Department of Energy (DOE) continues to face a major tank remediation problem with approximately 332 tanks storing over 378,000 ml of high-level waste (HLW) and transuranic (TRU) waste across the DOE complex. Most of the tanks have significantly exceeded their life spans. Approximately 90 tanks across the DOE complex are known or assumed to have leaked. Some of the tank contents are potentially explosive. These tanks must be remediated and made safe. How- ever, regulatory drivers are more ambitious than baseline technologies and budgets will support. Therefore, the Tanks Focus Area (TFA) began operation in October 1994. The focus area manages, coordinates, and leverages technology development to provide integrated solutions to remediate problems that will accelerate safe and cost-effective cleanup and closure of DOE`s national tank system. The TFA is responsible for technology development to support DOE`s four major tank sites: Hanford Site (Washington), INEL (Idaho), Oak Ridge Reservation (ORR) (Tennessee), and Savannah River Site (SRS) (South Carolina). Its technical scope covers the major functions that comprise a complete tank remediation system: safety, characterization, retrieval, pretreatment, immobilization, and closure.

The UCSD/TEXTOR collaboration has achieved the completion of three major tasks this year: (1) pump limiter studies; (2) RI-mode turbulence studies; and (3) velocity shear stabilization of turbulence. Brief summaries of progress in each area are given.