The U.S. Department of Energy (DOE) continues to face a major radioactive waste tank remediation problem with hundreds of waste tanks containing hundreds of thousands of cubic meters of high-level waste (HLW) and transuranic (TRU) waste across the DOE complex. Approximately 80 tanks are known or assumed to have leaked. Some of the tank contents have reacted to form flammable gases, introducing additional safety risks. These tanks must be maintained in a safe condition and eventually remediated to minimize the risk of waste migration and/or exposure to workers, the public, and the environment. However, programmatic drivers are more ambitious than baseline technologies and budgets will support. Science and technology development investments are required to reduce the technical and programmatic risks associated with the tank remediation baselines. The Tanks Focus Area (TFA) was initiated in 1994 to serve as the DOE`s Office of Environmental Management`s (EM`s) national technology development program for radioactive waste tank remediation. The national program was formed to increase integration and realize greater benefits from DOE`s technology development budget. The TFA is responsible for managing, coordinating, and leveraging technology development to support DOE`s four major tank sites: Hanford Site (Washington), Idaho National Engineering and Environmental Laboratory (INEEL) (Idaho), …

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The Hanford Site 200 Area Effluent Treatment Facility (ETF) processes contaminated liquids derived from Hanford Site facilities. Groundwater monitoring for tritium and other constituents is required by the state-issued permit at 22 wells surrounding the facility. Water level measurements in nearby wells indicate that a small hydraulic mound exists around the SALDS facility as a result of discharges. Evaluation of this condition indicates that the network is currently adequate for tracking potential effects of the SALDS on the groundwater. During FY 2000, average tritium activities in most wells declined from average activities in 1999. The exception was deep well 699-48-77C, where tritium results were at an all-time high (710,000 pCi/L) as a result of the delayed penetration of effluent deeper into the aquifer. Of the 12 constituents with permit enforcement limits, which are monitored in SALDS proximal wells, all were within groundwater limitations during FY 2000. Analyses for conductivity, total dissolved solids, sulfate, chloride, sulfate, dissolved calcium, and dissolved sodium indicate that well 699-48-77A and, to a lesser extent, well 699-48-77D show the effects of dilute effluent entering groundwater, resulting in a depression of concentrations of these constituents below natural background levels. Recommendations for future monitoring include temporarily increasing the …

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Laboratory tests were completed on the dissolution characteristics of Hanford saltcake waste from single-shell waste tanks 241-TX- 113, 241-BY-102, 241-BY-106, 241-A-101, and 241-S-102 (henceforth referred to as TX-113, BY-102, BY-106, A-101, and S-102, respectively). This work was funded by the Tanks Focus Area (EM-50) under Technical Task Plan Number RL0-8-WT-41, ''PHMC Pretreatment--Saltcake Dissolution''. The tests performed on saltcake from tank TX-113 were similar in scope to those completed in previous years on waste from tanks BY-102, BY-106, B-106, A-101, and S-102 (Herting 1998, 1999). In addition to the ''standard'' dissolution tests, new types of tests were performed this year related to feed stability and radionuclide distribution. The River Protection Project (RPP) is tasked with retrieving waste from double-shell and single-shell tanks to provide feed for vitrification. The RPP organization needs chemical and physical data to evaluate technologies for retrieving the waste. Little significant laboratory testing has been done to evaluate in-tank dissolution parameters for the various types of saltcake wastes that exist in single-shell tanks. A computer modeling program known as the Environmental Simulation Program (ESP), produced by OLI Systems, Inc of Morris Plains, New Jersey, is being used by the RPP organization to predict solubilities during dilution and retrieval …

This document describes the baseline single-shell tank (SST) waste retrieval sequence for the River Protection Project (RPP) updated for Fiscal Year 2000. The SST retrieval sequence identifies the proposed retrieval order (sequence), the tank selection and prioritization rationale, and planned retrieval dates for Hanford SSTs. In addition, the tank selection criteria and reference retrieval method for this sequence are discussed.