Challenge problem and milestones for : Nuclear Energy Advanced Modeling and Simulation (NEAMS) waste Integrated Performance and Safety Codes (IPSC).

Abstract

This report describes the specification of a challenge problem and associated challenge milestones for the Waste Integrated Performance and Safety Codes (IPSC) supporting the U.S. Department of Energy (DOE) Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign. The NEAMS challenge problems are designed to demonstrate proof of concept and progress towards IPSC goals. The goal of the Waste IPSC is to develop an integrated suite of modeling and simulation capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive waste storage or disposal system. The Waste IPSC will provide this simulation capability (1) for a range of disposal concepts, waste form types, engineered repository designs, and geologic settings, (2) for a range of time scales and distances, (3) with appropriate consideration of the inherent uncertainties, and (4) in accordance with robust verification, validation, and software quality requirements.To demonstrate proof of concept and progress towards these goals and requirements, a Waste IPSC challenge problem is specified that includes coupled thermal-hydrologic-chemicalmechanical (THCM) processes that describe (1) the degradation of a borosilicate glass waste form and the corresponding mobilization of radionuclides (i.e., the processes that produce the radionuclide source term), (2) the associated near-field physical and chemical environment for waste emplacement within a salt formation, and (3) radionuclide transport in the near field (i.e., through the engineered components -waste form, waste package, and backfill -and the immediately adjacent salt). The initial details of a set of challenge milestones that collectively comprise the full challenge problem are also specified.iii iv CONTENTS

Nuclear Energy Advanced Modeling and Simulation (NEAMS) Waste Integrated Performance and Safety Codes (IPSC) : FY10 development and integration.

“…These activities build upon the Waste IPSC system design specifications outlined in SNL (2009). The challenge problem specifications are documented in Freeze et al (2010) and the V&V plan is documented in Edwards et al (2010). This report describes the progress in FY10 in the other two activities, the development and integration of (a) THCM code capabilities, and (b) frameworks and enabling tools and infrastructure.…”

“…The Enabling Infrastructure is also required to support the challenge problem and milestones identified in Freeze et al (2010). Many tools and capabilities of the Enabling Infrastructure will be needed for FY11 tasks and milestones.…”

NEAMS Nuclear Waste Management IPSC : evaluation and selection of tools for the quality environment.

“…These tools will be exercised and evaluated within the context of the NEAMS Nuclear Waste Management IPSC Challenge Problem milestones [2]. It is intended that this experience will lead to improvements in the use of selected tools, feedback to tool developers for improvements to the tools, or possibly require selection of new tools.…”

Nuclear Energy Advanced Modeling and Simulation (NEAMS) waste Integrated Performance and Safety Codes (IPSC) : gap analysis for high fidelity and performance assessment code development.

“…A set of 6 potential waste form type groupings (Table 1) and 8 potential disposal concept/geologic setting groupings (Table 2) were identified to define the expected range (based on current knowledge) of disposal system concepts, designs, settings and conditions (Freeze et al 2010a, Section 2.1; Freeze et al 2010b, Section 2.1). These groupings result in 35 combinations (ignoring the placeholder -Other‖ groups) of waste form types and disposal concepts/geologic settings that broadly define the range of potential alternative disposal system designs that might need to be evaluated using the Waste IPSC.…”

“…These activities build upon the Waste IPSC system design specifications outlined in SNL (2009). The specifications of the challenge problems and associated milestones, designed for testing and tracking the progress of the IPSC code development, are documented in Freeze et al (2010a). The V&V plan is documented in Edwards et al (2010) and the preliminary THCMBR code gap analysis is summarized in Freeze at al.…”