Tank waste decision analysis report

The Assistant Secretary for Environmental Restoration and Waste Management and the director of the Washington State Department of Ecology agreed to the need to re-evaluate treatment and disposal plans for Hanford Site tank waste. Re-evaluation of the tank waste treatment and disposal plans (referred to as rebaselining) was necessary to (1) provide an integrated system approach for achieving safe storage, (2) resolve tank safety issues, and (3) treat and dispose of all Hanford Site tank waste. Rebaselining evaluated new approaches to remediate Hanford Site tank waste and, thus, reaffirm existing plans or recommend a new technical strategy. To facilitate this integrated system approach for managing the program elements, the US Department of Energy formed the Tank Waste Remediation System (TWRS). While conducting this re-evaluation, the US Department of Energy agreed to continue supporting the existing plan for treatment and disposal of Hanford Site tank waste. The selection of a proposed new technical strategy for the TWRS Program is a complex task involving the evaluation of a large body of data. The data that is available to support the selection of a proposed new technical strategy is based on engineering estimates and preliminary technology development. To accommodate this complex, dynamic situation,more » a systems engineering approach is being applied to structure and analyze technical strategies and to manage the TWRS Program. Systems engineering is a generalized and systematic methodology for defining problems, evaluating solutions, and implementing the solutions. This report describes the development of the TWRS Program systems engineering analysis, the analytical methodologies that support it, and the results of the analyses that were used to define the proposed new technical strategy.« less