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A multigroup moment-accelerated deterministic particle solver for 1-D time-dependent thermal radiative transfer problems
We introduce an efficient, robust, Lagrangian (characteristic-based) transport solver for 1-D time-dependent thermal radiative transfer (TRT) applications within the context of a moment-accelerated (High-Order/Low-Order, HOLO) algorithm. This novel transport algorithm inherits the best features of both particle methods (e.g., time accuracy, phase-space adaptivity, positivity) and deterministic, grid-based methods (e.g., no stochastic noise). Particles are adapted by the method of characteristics, with a time-dependent weight that accounts for stiff absorption and reemission process self-consistently. As a result, this approach is able to obtain accurate results while employing large time steps and a moderate number of particles (compared to Implicit Monte Carlo).
Modeling fission spikes in nuclear fuel using a multigroup model of electronic energy transport
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A lumped parameter method of characteristics approach and multigroup kernels applied to the subgroup self-shielding calculation in MPACT
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Analysis of the multigroup model for muon tomography based threat detection
We compare different algorithms for detecting a 5 cm tungsten cube using cosmic ray muon technology. In each case, a simple tomographic technique was used for position reconstruction, but the scattering angles were used differently to obtain a density signal. Receiver operating characteristic curves were used to compare images made using average angle squared, median angle squared, average of the squared angle, and a multi-energy group fit of the angular distributions for scenes with and without a 5 cm tungsten cube. The receiver operating characteristic curves show that the multi-energy group treatment of the scattering angle distributions is the superior method for image reconstruction.
Multigroup Cross Section Generation with the Shift Monte Carlo Code
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Multigroup Radiation Transport in Supernova Light Curve Calculations
The supernova associated with long duration gamma0ray bursts are always found to be Type Ic supernova (SN). Type Ic SN are observed to have extremely small amounts of He in their spectra. Astrophysicists have been exploring ways to either hide the He in the observations or eject the He prior to the SN. Recent calculations by Patrick Young using new mixing algorithms suggest that many massive stars may burn the He layer to O during its evolution and therefore naturally account for the lack of He in the spectra of the SN. The LANL supernova light curve codes are being used to generate simulated observations of these new models.
Consistent Multigroup Theory Enabling Accurate Course-Group Simulation of Gen-IV Reactors
The objective of this proposal is the development of a consistent multi-group theory that accurately accounts for the energy-angle coupling associated with collapsed-group cross sections. This will allow for coarse-group transport and diffusion theory calculations that exhibit continuous energy accuracy and implicitly treat cross- section resonances. This is of particular importance when considering the highly heterogeneous and optically thin reactor designs within the Next Generation Nuclear Plant (NGNP) framework. In such reactors, ignoring the influence of anisotropy in the angular flux on the collapsed cross section, especially at the interface between core and reflector near which control rods are located, results in inaccurate estimates of the rod worth, a serious safety concern. The scope of this project will include the development and verification of a new multi-group theory enabling high-fidelity transport and diffusion calculations in coarse groups, as well as a methodology for the implementation of this method in existing codes. This will allow for a higher accuracy solution of reactor problems while using fewer groups and will reduce the computational expense. The proposed research represents a fundamental advancement in the understanding and improvement of multi- group theory for reactor analysis.
Development of the V4.2m5 and V5.0m0 Multigroup Cross Section Libraries for MPACT for PWR and BWR
The MPACT neutronics module of the Consortium for Advanced Simulation of Light Water Reactors (CASL) core simulator is a 3-D whole core transport code being developed for the CASL toolset, Virtual Environment for Reactor Analysis (VERA). Key characteristics of the MPACT code include (1) a subgroup method for resonance selfshielding and (2) a whole-core transport solver with a 2-D/1-D synthesis method. The MPACT code requires a cross section library to support all the MPACT core simulation capabilities which would be the most influencing component for simulation accuracy.
MCNP tallied weight functions to improve multigroup simulations
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Adapting CLUTCH Methodology to Multigroup TSUNAMI-3D for Eigenvalue Sensitivity Calculations [Slides]
Abstract not provided.
Mulard: A Multigroup Thermal Radiation Diffusion Mini-Application
Abstract not provided
Radiation multigroup diffusion for refractive, lossy media in ALE3D (U)
Abstract not provided
Mixed Uranium-Plutonium Solution Validation of KENO V.a and KENO-VI in SCALE 6.1.2 and 6.2b3 Using Multigroup and Continuous-Energy ENDF/B-VII.0 Libraries
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Multigroup Data Processing for the Embedded Self-Shielding Method in SCALE
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A Case Study in the Application of TSUNAMI-3D Part 1, Multigroup
The use of the sensitivity and uncertainty tool suite within SCALE, known as the TSUNAMI suite, has grown following its initial introduction more than a decade ago. Proper use of these tools provides a more complete understanding of system responses to perturbations, especially in the area of nuclear cross section uncertainties. Recent advances within TSUNAMI have added generalized perturbation theory to the keff sensitivity capability that was included in TSUNAMI originally. The generation of sensitivity data is encouraged in the review process for new critical experiment requests sponsored by the US Department of Energy (DOE) Nuclear Criticality Safety Program (NCSP)to demonstrate that the proposed experiment will satisfy the identified data need. Many individuals participate in this process, but many analysts have not received proper training in the use of the TSUNAMI tools. The adjoint perturbation theory used to calculate sensitivities is not typically included in nuclear engineering curricula, leaving inexperienced engineers particularly at risk for incorrect use of the tools.
A Multigroup, Lumped Parameter MOC Method for Subgroup Self-Shielding in MPACT
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