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The Department of Energy's (DOE) Savannah River Site (SRS) high-level waste program is responsible for storage, treatment, and immobilization of high-level waste for disposal. The Salt Processing Program (SPP) is the salt (soluble) waste treatment portion of the SRS high-level waste effort. The overall SPP encompasses the selection, design, construction and operation of treatment technologies to prepare the salt waste feed material for the site's grout facility (Saltstone) and vitrification facility (Defense Waste Processing Facility). Major constituents that must be removed from the salt waste and sent as feed to Defense Waste Processing Facility include actinides, strontium, cesium, and entrained sludge. In fiscal year 2002 (FY02), research and development (R&D) on the actinide and strontium removal and Caustic-Side Solvent Extraction (CSSX) processes transitioned from technology development for baseline process selection to providing input for conceptual design of the Salt Waste Processing Facility. The SPP R&D focused on advancing the technical maturity, risk reduction, engineering development, and design support for DOE's engineering, procurement, and construction (EPC) contractors for the Salt Waste Processing Facility. Thus, R&D in FY02 addressed the areas of actual waste performance, process chemistry, engineering tests of equipment, and chemical and physical properties relevant to safety. All of the …

This report is one of two components, the first an overview document outlining the goals and results of the XFEM LDRD project, and the other (titled ''Structured Extended Finite Element Methods of Solids defined by Implicit Surfaces'') detailing the scientific advances developed under FY01/FY02 LDRD funding. The XFEM (Extended Finite-Element Method) Engineering LDRD/ER Project was motivated by three research and development goals: (1) the extensions of standard finite-element technology into important new research venues of interest to the Engineering Directorate, (2) the automation of much of the engineering analysis workflow, so as to improve the productivity of mesh-generation and problem setup processes, and (3) the development of scalable software tools to facilitate innovation in XFEM analysis and methods development. The driving principle behind this LDRD project was to demonstrate the computational technology required to perform mechanical analysis of complex solids, with minimal extra effort required on the part of mechanical analysts. This need arises both from the growing workload of LLNL analysts in problem setup and mesh generation, and from the requirement that actual as-built mechanical configurations be analyzed. Many of the most important programmatic drivers for mechanical analysis require that the actual (e.g., deformed, aged, damaged) geometric configuration of …