Verification & Validation

Above image: Validation comparison for large deformation of a metal housing due to drop impact. (Sandia National Laboratories)

Verification and Validation (V&V) provides assurance that the models in the codes produce mathematically correct answers and that the answers reflect physical reality. The V&V subprogram funds the critical skills needed to apply systematic measurement, documentation, and demonstration of the ability of the models and codes to predict physical behavior. The V&V subprogram is developing and implementing Uncertainty Quantification (UQ) methodologies as part of the foundation to the Quantification of Margins and Uncertainties (QMU) process of weapons assessment and certification. The V&V subprogram also drives software engineering practices to improve the quality, robustness, reliability, and maintainability of the codes that evaluate and address the unique complexities of the stockpile. As nuclear test data is becoming less relevant with an aging stockpile and as weapons designers with test experience leave the Nuclear Security Enterprise, (NSE) it becomes increasingly important that the codes of the NSE are verified and validated so future generations of designers are comfortable relying on these foundational tools.

Benefits

The Verification and Validation subprogram provides methods and measures necessary to assess the credibility of the ASC codes and models, quantify uncertainties in ASC calculation results, measure the progress in the ASC predictive capabilities, and provide confidence when applying simulations for stockpile deliverables.

V&V Methods

This area provides methods and measures necessary to assess the credibility of the ASC codes and models, quantify uncertainties in ASC calculation results, and measure the progress in the ASC predictive capabilities. In this role, V&V will be aware of leading research, perform its own research, and be an advocate for advanced research and methods development in the areas of code verification, solution verification, validation metrics and methodology, and uncertainty quantification (UQ) as enabling technologies for validation and quantification of margins and uncertainties (QMU) in a risk-informed decision context.

V&V Assessments

This area delivers science-based assessments of the predictive capability and uncertainties in ASC integrated performance, engineering, and specialized codes’ phenomenological models, numerical methods, and related models, to support the needs of the Stockpile Stewardship Program. This area focuses on establishing credibility in integrated simulation capabilities by collecting evidence that the numerical methods and simulation models are being solved correctly, and whether the simulation results from the mathematical and computational models implemented into the codes agree with real-world observations. This requires extensive collaboration with the various ASC elements, DSW, and the Science and Engineering Campaigns.

Data Validation, Archiving, SQA, and Training

This area provides traceable and reproducible work products and processes for stockpile certification (short and long term), as well as foundational elements for establishing software quality standards and training weapons scientists in the application of verification, validation, and UQ methods. The scope of this product includes integral validation of physical property data that that are used as inputs for various weapon relevant simulations. Additionally, this product includes work product and data archiving and simulation pedigree tracking. It also includes establishing high-level software quality requirements, assessment techniques and methods, and development of Software Quality Engineering (SQE) tools. Finally, it supports the adoption of stockpile QMU assessment methodologies through computational simulation by providing training for use of V&V and UQ tools to establish credible simulation-based performance margin and uncertainty estimates.