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At least 1,783 records · Page 99

Sierra Structural Dynamics Code Verification Plan

Verification and validation (V&V) of scientific computing programs are important at San- dia National Laboratories (SNL) due to the expanding role of computational simulation in managing the United States nuclear stockpile. This document presents the verification plan for the Sierra Structural Dynamics application. This verification plan includes code devel- opment practices, structure of test suites, and additional quality assurance practices used by the Sierra/SD team.

42 ENGINEERING↗

Activation of Th-232 target using FLUKA simulation code

FLUKA is a general-purpose Monte Carlo simulation code used to model the interaction and transport of particles from a few KeV to thousands of TeV in arbitrary materials. It is built and maintained with the aim of including the best possible physical models in terms of completeness and precision [1]. In this study, we are using the USRBDX card to get the energy spectrum (photons/sec), RESNUCLEi card to score the residual isotopes and activities and USRBIN card to calculate the dose rate from the Thorium target irradiated in the BLIP.

43 PARTICLE ACCELERATORS↗

The ray-tracing code Zgoubi - latest developments

The reader is referred to the ICFA-BD-NL No.43, and to a more recent status article in NIMA, regarding the technical details of the Zgoubi tracking engine and its accuracy, which make it "near-symplectic" - sufficiently so to model millions of turns in large hadron colliders, - and its potential for pushing particles in complex accelerator structures and accelerator optical elements or their field maps. Extended documentation can be found in the regular FFA workshops as well as in the SourceForge code development site where in particular many examples of beam lines, FFAs and other ring simulations are maintained. There is also a comprehensive user's guide. Further documentation, including an attempt to demonstrate 6D simulation in all possible types of particle accelerators, can be found in the "Computer Laboratory" Stony Brook University "PHY689" semester series.

43 PARTICLE ACCELERATORS↗

Architectural Basis for Highly Distributed Transactive Power Grids: Frameworks, Networks, and Grid Codes

This paper provides an architectural framework for highly distributed Transactive Energy grids. This framework guides the engineering of transactive distribution systems, informs the necessary interoperability standards, and fills in the gap in the ability of electric distribution utilities to write the Grid Codes that define how prosumer and third party devices plug into such a grid. With this architecture, a major hurdle to Transactive Grid deployment is resolved.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Material Model Testing in the DYNA3D Code: Material Models 6 through 10

This report is the second volume in an effort to study the material model implementations in DYNA3D, using the latest developmental version of the code. Input files were derived from a template supplied by Jerry Lin to perform an equation-of-state study. Most of the simulations use 10 cubes, each 1 cm on a side with a density of 8.03 (steel). Each of the cubes tests a different aspect of the material model. This document will discuss the testing of Material Models 6 through 10. Relevant results from the test cubes will be discussed. A discussion of the results from all 10 test cubes will be presented only if necessary.

42 ENGINEERING↗

Multiple Phase Screen Scintillation Modeling Code

This document describes the underlying theory and use of a computer code written to simulate scintillation effects on propagating electromagnetic (EM) signals. The Multiple Phase Screen (MPS) technique [1, 2, 3, 4] is employed to model the effects of scintillation on EM signals as they travel through the earth’s ionosphere.

97 MATHEMATICS AND COMPUTING↗

Report on FY19 Testing in Support of Grade 91 Core Block Code Case

This report summarizes the experimental results performed in FY 2019 on grade 91 (Gr. 91) steel (heat 30176) in support of Gr. 91 core block code cases. Mean stress fatigue testing was completed, and the evaluation led to the conclusion that mean stress correction on the fatigue curve in Division 5 for Gr. 91 is not recommended. A specialized test was designed and performed to validate the methodology proposed for a softening factor to support the extension of the elastic—perfectly plastic (EPP) strain limits design rules to Gr. 91. Nine simplified model tests (SMTs) were completed using the newly developed two-bar SMT (TBSMT) and single-bar SMT (SBSMT) techniques. The results demonstrate the validity of the testing technique, and the experimental basis of the development of the integrated EPP plus SMT creepfatigue evaluation methodology.

36 MATERIALS SCIENCE↗

CogSim: Integrate ML-based Library (LAGER) into Multi-Physics Simulation Code

In LAGER, the Mesh and Simulation History Extract (MASHExtract) package has been used for extracting various types of data from Kull runs. The package itself was written in python and completely enmeshed in the Kull codebase, making it impossible to use with other simulations. Having a version that extends to the Ale3d codebase would necessitate a complete re-write of the package, including a conversion to the C++ language. Extending the MASHExtract package to Ale3d requires a level of simulation independence, much of which would come from handling user requests, data management, and exporting. However, there is still a section of code that would need to be able to handle extracting data from the target codebase. Because of the often insurmountable differences between simulation codebases, the MASHExtract package would need a specific layer to be implemented for each codebase that handles this process of collecting and organizing the requested data. Furthermore, different simulation codebases also have different requirements for various enhancements they rely on—user interface, multi processor distribution, gpu acceleration, etc—all of which would also need to be handled by this layer. In regards to Kull and Ale3d specifically, the Kull implementation (KullMASHExtract) will need to be wrapped in Python, and Ale3d (Ale3dMASHExtract) will need to be wrapped in RAJA. Since Kull is primarily wrapped in SWIG, we should also use this library for our own wrapping to maintain consistency. There are also differences between what metrics are available for extraction. In particular, Kull has a wide array of physics metrics that may not be available in Ale3d, and these differences will need to be accounted for when re-writing MASHExtract.

97 MATHEMATICS AND COMPUTING↗

Nonlinear Optimization in "Synchrotron Radiation Workshop" Code

"Synchrotron Radiation Workshop" (SRW) is an open source physical optics computer code for calculation of detailed characteristics of Synchrotron Radiation (SR) generated by relativistic electrons in magnetic fields of arbitrary configuration. SRW also supports high-accuracy simulations of fully- and partially-coherent radiation propagation through X-ray optical beamlines, facilitated by so-called “Virtual Beamline” module. In this present tech note, we discuss the nonlinear optimization features of SRW with emphasis on the optimization library in SRW. This optimization library not only can be used to optimize the simulation beamline in SRW, it also can be integrated with real beamline operations and optimize the parameters based on real measurements. We also show some demos of the optimization library recently developed in SRW.

36 MATERIALS SCIENCE↗

SURF Model Resolution in xRage Code

A key issue for detonation wave simulations with a reactive burn model is the resolution needed for the reaction zone. The reaction-zone width is a physical length scale. For plastic-bonded explosives, it is small (on the order of 100 microns) but affects important detonation properties such as the detonation speed. Even with adaptive mesh refinement, a well resolved reaction zone is computationally expensive. Here we consider the trade-off between computational expense and accuracy when the resolution of the reaction zone is varied for simulations with the xRage code of PBX 9501 with the SURF burn model and of PBX 9502 with the SURFplus burn model. For assessing shock initiation, the numerical Pop plot is simulated, and for assessing propagating detonation waves, the cylinder test is used as a test problem. The reaction-zone resolution is varied from a cell size of 6.25 to 200 microns, and key properties of the solutions are compared. With 6 micron resolution, the numerical solution is near mesh converged and can be used to judge the accuracy of the coarser resolution simulations. For the propagating detonation wave in the cylinder test, at 200 microns the detonation speed is low by a couple of per cent. In terms of cpu-hours, the finest resolution is about a factor of 100 more expensive than the coarsest resolution.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

Recent SAM Code Improvement to Heat Transfer Modeling Capabilities

System Analysis Module (SAM) is currently under development at Argonne National Laboratory as a modern system-level modeling and simulation tool for advanced non-light water reactor (non-LWR) safety analyses. It utilizes the object-oriented application framework MOOSE to leverage the modern software environment and advanced numerical methods. The capabilities of SAM are being extended to enable the transient modeling, analysis, and design of various advanced nuclear reactor systems. This report summarizes recent SAM code improvement to heat transfer modeling capabilities to support system and core thermal-hydraulics analysis for advanced nuclear reactor systems. These new capabilities include implementation of the energy equation for solid structure in porous medium and its coupling with porous medium flow energy equation; coupling between one-dimensional flow equation and three-dimensional heat conduction equation; coupling between two-dimensional heat structure and three-dimensional porous medium flow equations; and implementation of effective thermal conductivity correlations for solid pebble beds and its validation against High Temperature Test Unit (HTTU) experimental data. Demonstration or validation test problems are also included in this report to confirm the successful implementation of these capabilities.

1D/3D coupling↗

Testing the HM-5s and NaIGEM code

We tested the performance of the HM-5 units and the NaIGEM code to determine the uranium enrichment. The uranium materials consist of two groups, the NBS series and the UISO series. The NBS items are U 3 O 8 in aluminum containers with an inner diameter of 7.0 cm and a frontal surface thickness of 2.0 mm. The UISO items are U 3 O 8 stored in doubly encapsulated stainless steel containers with a total thickness of 0.82 mm. The diameter of the inner UISO container is 10.0 cm. Four separate tests were performed.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

SCALE Code System

The SCALE Code System is a widely used modeling and simulation suite for nuclear safety analysis and design that is developed, maintained, tested, and managed by the Reactor and Nuclear Systems Division (RNSD) of Oak Ridge National Laboratory (ORNL). SCALE provides a comprehensive, verified and validated, user-friendly tool set for criticality safety, reactor and lattice physics, radiation shielding, spent fuel and radioactive source term characterization, and sensitivity and uncertainty analysis. Since 1980, regulators, licensees, and research institutions around the world have used SCALE for safety analysis and design. SCALE provides an integrated framework with dozens of computational modules, including three deterministic and three Monte Carlo radiation transport solvers that are selected based on the desired solution strategy. SCALE includes current nuclear data libraries and problem-dependent processing tools for continuous-energy (CE) and multigroup (MG) neutronics and coupled neutron-gamma calculations, as well as activation, depletion, and decay calculations. SCALE includes unique capabilities for automated variance reduction for shielding calculations, as well as sensitivity and uncertainty analysis. SCALE’s graphical user interfaces assist with accurate system modeling, visualization of nuclear data, and convenient access to desired results.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Training for Cost-Effective Code-Compliant Maintenance Facilities

The overarching goal for this project was to create training and guidance materials about garage upgrades and building modifications for facilities that service natural gas, propane, and/or hydrogen vehicles. Toward this end, the technical approach involved educating key stakeholders, such as Code Officials and Authorities Having Jurisdiction (AHJs).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Applicability of the ARCON96 Code to the Radiological Consequence Analysis of Releases from the Radioassay and Non-Destructive Testing (RANT) Facility

Establish technical justification to demonstrate that the horizontal diffusion parameter (σy) and vertical diffusion parameter (σz) that are embedded in the Nuclear Regulatory Commission (NRC) Atmospheric Relative CONcentrations (ARCON96) code are representative of the meteorological conditions at LANL. Compare the ARCON96 atmospheric diffusion factor ( X /Q) to the MACCS2-calculated X /Q for the determination of radiological consequences of ground releases from the Radioassay and Non-Destructive Testing (RANT) facility on the key receptors, the colocated worker (CW) and Maximally-Effected Offsite Individual (MEOI).

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

Demonstration of a new unstructured mesh IMC x-ray transport capability in LAP codes

The Advanced Simulation and Computing (ASC) Transport project’s Jayenne Implicit Monte Carlo (IMC) transport library now includes an unstructured mesh capability and is available in a Lagrangian Applications Project (LAP) code. In this presentation, we discuss recent work by the LAP and Transport projects that provides an IMC transport capability for radiation hydrodynamics in the Lagrangian frame. Verification problems testing the new capabilities have been simulated and analyzed, i.e. Marshak wave, Mach 45, Su-Olsen, picket fence, and crooked pipe, both in one and two dimensions. We also present results on two stretch goal problems: a simplified COAX high energy density physics experiment and a supernova shock simulation. Finally, we identify current limitations and future work needed to bring a full capability to the user community.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Engineering scale molten salt corrosion and chemistry code development

A new engineering scale transport code Mole is described. Mole was developed using the Multiphysics Object-Oriented Simulation Environment (MOOSE) framework for solving species transport problems in flowing liquid. It is applied to leaching of Cr from alloys into molten salts part a of a multi-physics, multi-scale approach for coupling chemistry with mechanical behavior modeling. Demonstrations of the leaching phenomenon were benchmarked to experimental data provided by the Molten Salt Reactor campaign and the results are presented.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗