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DOE OSTI2022

Python Codebase and Jupyter Notebooks - Applications of Machine Learning Techniques to Geothermal Play Fairway Analysis in the Great Basin Region, Nevada

Git archive containing Python modules and resources used to generate machine-learning models used in the "Applications of Machine Learning Techniques to Geothermal Play Fairway Analysis in the Great Basin Region, Nevada" project. This software is licensed as free to use, modify, and distribute with attribution. Full license details are included within the archive. See "documentation.zip" for setup instructions and file trees annotated with module descriptions.

Brown, Stephen↗

DOE OSTI2012

DHS Written Report

Recently, a new galactic cosmic-ray (GCR) source option [1] was implemented in the all-energy, all-particle transport code MCNP6 [2]. In this paper, we made use of this feature to calculate surface neutron and photon background fluxes on a terrestrial grid around the earth. These spectra have been incorporated into Release 2 of the 'background.dat' file, which is read and sampled by MCNP6 whenever a user invokes the background source option [2]. Cosmic radiation bombards Earth with various particles, such as protons and {alpha} particles, some of which are deflected by the Earth's shielding magnetic field. Particles that carry sufficient energy can overcome the deflection and penetrate into the atmosphere. The sufficient energy is dependent on the terrestrial coordinates due to the magnetic force's proportionality to the sine of the angle between the velocity vector of the incoming particle and the magnetic field. As the particles propagate through the atmosphere, collisions with atmospheric molecules generate new particles such as neutrons, protons, photons, muons, pions, and other exotic particles. These secondary often have sufficient energy to undergo additional nuclear interactions, and so on, forming what is known as a cascade shower. The tabulation of background particle fluxes on the surface of the earth is important for a variety of reasons, one of which is the design of nuclear material detection systems. The simulations used various models and formulations for the cosmic source spectra, atmosphere, and terrestrial conditions to correctly model the propagation of GCR particles through the atmosphere to surface level.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

NASA NTRS1992

An efficient HZETRN (a galactic cosmic ray transport code)

An accurate and efficient engineering code for analyzing the shielding requirements against the high-energy galactic heavy ions is needed. The HZETRN is a deterministic code developed at Langley Research Center that is constantly under improvement both in physics and numerical computation and is targeted for such use. One problem area connected with the space-marching technique used in this code is the propagation of the local truncation error. By improving the numerical algorithms for interpolation, integration, and grid distribution formula, the efficiency of the code is increased by a factor of eight as the number of energy grid points is reduced. The numerical accuracy of better than 2 percent for a shield thickness of 150 g/cm(exp 2) is found when a 45 point energy grid is used. The propagating step size, which is related to the perturbation theory, is also reevaluated.

Shinn, Judy L.↗

DOE OSTI2023

ERF: Energy Research and Forecasting

The Energy Research and Forecasting (ERF) code is a new model that simulates the mesoscale and microscale dynamics of the atmosphere using the latest high-performance computing architectures. It employs hierarchical parallelism using an MPI+X model, where X may be OpenMP on multicore CPU-only systems, or CUDA, HIP, or SYCL on GPU-accelerated systems. ERF is built on AMReX (Zhang et al., 2019, 2021), a block-structured adaptive mesh refinement (AMR) software framework that provides the underlying performance-portable software infrastructure for block-structured mesh operations. The "energy" aspect of ERF indicates that the software has been developed with renewable energy applications in mind. In addition to being a numerical weather prediction model, ERF is designed to provide a flexible computational framework for the exploration and investigation of different physics parameterizations and numerical strategies, and to characterize the flow field that impacts the ability of wind turbines to extract wind energy. The ERF development is part of a broader effort led by the US Department of Energy's Wind Energy Technologies Office.

17 WIND ENERGY↗

DOE OSTI2015

A comparison of anisotropic and isotropic grain growth simulation results of Uranium dioxide and Copper

Grain boundaries migrate to reduce the total grain boundary energy in a material. However, grain boundary energy is anisotropic, such that some grain boundaries are less energy favorable in the system and tend to disappear. Idaho National Laboratory’s (INL) mesoscale fuel performance code MARMOT currently assumes isotropic (non-directionally dependent) grain boundary energy in all phase field sim- ulations of grain boundary migration. As a preliminary step to incorporating fully anisotropic grain boundary energies into MARMOT, a comparison of the results of grain growth simulations for UO 2 nuclear fuels utilizing the old isotropic MARMOT code and new code incorporating anisotropic grain boundary energies was performed. Comparisons of Copper simulations were also performed. The re- sults analyzed were from simple circle and thumb-shaped grain test cases, and polycrystalline systems using artificially generated initial conditions. The metrics used to compare the grains from isotropic and anisotropic cases include grain area and average grain boundary energy. Anisotropic behavior was observed in the systems of circle and thumb-shaped grains. Polycrystalline systems do not behave as expected, suggesting missing terms in the equation implemented in MARMOT which governs the mi- crostructural evolution of the grain boundaries.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2022

An energy-based study of the embedded element method for explicit dynamics

Abstract The embedded finite element technique provides a unique approach for modeling of fiber-reinforced composites. Meshing fibers as distinct bundles represented by truss elements embedded in a matrix material mesh allows for the assignment of more specific material properties for each component rather than homogenization of all of the properties. However, the implementations of the embedded element technique available in commercial software do not replace the material of the matrix elements with the material of the embedded elements. This causes a redundancy in the volume calculation of the overlapping meshes leading to artificially increased stiffness and mass. This paper investigates the consequences in the energy calculations of an explicit dynamic model due to this redundancy. A method for the correction of the edundancy within a finite element code is suggested which removes extra energy and is shown to be effective at correcting the energy calculations for large amounts of redundant volume.

Martin, Valerie A.↗

NASA NTRS2009

Monte Carlo Analysis of Pion Contribution to Absorbed Dose from Galactic Cosmic Rays

Accurate knowledge of the physics of interaction, particle production and transport is necessary to estimate the radiation damage to equipment used on spacecraft and the biological effects of space radiation. For long duration astronaut missions, both on the International Space Station and the planned manned missions to Moon and Mars, the shielding strategy must include a comprehensive knowledge of the secondary radiation environment. The distribution of absorbed dose and dose equivalent is a function of the type, energy and population of these secondary products. Galactic cosmic rays (GCR) comprised of protons and heavier nuclei have energies from a few MeV per nucleon to the ZeV region, with the spectra reaching flux maxima in the hundreds of MeV range. Therefore, the MeV - GeV region is most important for space radiation. Coincidentally, the pion production energy threshold is about 280 MeV. The question naturally arises as to how important these particles are with respect to space radiation problems. The space radiation transport code, HZETRN (High charge (Z) and Energy TRaNsport), currently used by NASA, performs neutron, proton and heavy ion transport explicitly, but it does not take into account the production and transport of mesons, photons and leptons. In this paper, we present results from the Monte Carlo code MCNPX (Monte Carlo N-Particle eXtended), showing the effect of leptons and mesons when they are produced and transported in a GCR environment.

Aghara, S.K.↗

DOE OSTI2016

Codes Don't Always Get Enforced, But Contracts Do: Changing the Procurement Paradigm to Drive Building Energy Performance

New construction could account for more than 25% of the U.S. energy consumption by 2030. Millions of square feet are built every year that will not perform as expected - despite advancing codes, rating systems, super-efficient technologies, and advanced utility programs. With retrofits of these under-performers decades away, savings potential will be lost for years to come. Only the building owner is in the driver's seat to demand - and verify - higher-performing buildings. Yet our current policy and market interventions really target the design team, not the owner. Accelerate Performance, a U.S. Department of Energy funded initiative, is changing the building procurement approach to drive deeper, verified savings in three pilot states: Illinois, Minnesota, and Connecticut. Performance-based procurement ties energy performance to design and contractor team compensation while freeing them to meet energy targets with strategies most familiar to them. The process teases out the creativity of the design and contracting teams to deliver energy performance - without driving up the construction cost. The paper will share early results and lessons learned from new procurement and contract approaches in government, public, and private sector building projects. The paper provides practical guidance for building owners, facilities managers, design, and contractor teams who wish to incorporate effective performance-based procurement for deeper energy savings in their buildings.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

NASA NTRS1981

The three dimensional spherical model for the AGCE

The development of accurate numerical model of the atmospheric general circulation experiment (AGCE) is discussed. The model will serve both as a design and diagnostic tool for the AGCE, as well as for conducting numerical experiments which otherwise cannot be performed by AGCE. The code in its final form will solve the complete three dimensional nonlinear Navier-Stokes energy equations with the Boussinesq approximation. The code will allow for any thermal boundary conditions and any external forcing in the form of rotation and body forces and will allow for variable thermodynamic coefficients.

Antar, B. N.↗

DOE OSTI2013

Collisional particle-in-cell modeling for energy transport accompanied by atomic processes in dense plasmas

Fully relativistic collisional Particle-in-Cell (PIC) code, PICLS, has been developed to study extreme energy density conditions produced in intense laser-solid interaction. Recent extensions to PICLS, such as the implementation of dynamic ionization, binary collisions in a partially ionized plasma, and radiative losses, enhance the efficacy of simulating intense laser plasma interaction and subsequent energy transport in resistive media. Different ionization models are introduced and benchmarked against each other to check the suitability of the model. The atomic physics models are critical to determine the energy deposition and transport in dense plasmas, especially when they consist of high Z (atomic number) materials. Finally we demonstrate the electron transport simulations to show the importance of target material on fast electron dynamics.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2012

Characterizing the energy distribution of laser-generated relativistic electrons in cone-wire targets

Transport of relativistic electrons in a solid Cu wire target has been modeled with the implicit hybrid particle-in-cell code LSP to investigate the electron energy distribution and energy coupling from the high-intensity, short-pulse laser to electrons entering to the wire. Experiments were performed on the TITAN laser using a 1.5 mm long Cu wire attached to a Au cone tip at the laser intensity of 1 Multiplication-Sign 10{sup 20} W/cm{sup 2} which was irradiated into the cone. The simulated Cu K{alpha} wire profile and yields matched the measurements using a two-temperature energy distribution. These modeling results show that the cold component of the energy spectrum can be determined with {+-}100 keV accuracy from the fit to the initial experimental fall-off of the K{alpha} emission while the simulated profiles were relatively insensitive to the hotter component of the electron distribution (>4 MeV). The slope of measured escaped electrons was used to determine the hotter temperature. Using exponential energy distributions, the laser-to-electron-in-wire coupling efficiencies inferred from the fits decreased from 3.4% to 1.5% as the prepulse energy increases up to 1 J. The comparison of the energy couplings using the exponential and Relativistic Maxwellian distribution functions showed that the energy inferred in the cold component is independent of the type of the distribution function.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2014

ADVANTG Results for a Proposed NDA System for Detecting Pin Diversion from SNF - Paper 120

This summary describes the results of applying the ADVANTG variance reduction parameter generator to accelerate continuous-energy Monte Carlo simulations of the {sup 252}Cf Interrogation with Prompt Neutron (CIPN) detection system proposed by Hu et al. for detecting the diversion of fuel elements from spent nuclear fuel (SNF) assemblies. In previous work, ADVANTG was applied to a suite of nine radiation detection, special nuclear material (SNM) movement detection, and safeguards test cases. That effort demonstrated that ADVANTG was able to provide large increases in tally figures of merit (FOMs) in nearly all of the cases without introducing bias into the Monte Carlo results. The objective of the work described here is to further evaluate ADVANTG, and also to identify gaps in capability with regard to nuclear safeguards applications, by applying the code to a challenging problem that is of a different nature from the ones previously studied. The CIPN nondestructive assay (NDA) system consists of three fission chambers embedded in a C-shaped block of polyethylene and a polyethylene-moderated {sup 252}Cf source that are placed on opposite sides of a subject SNF assembly. The idea of the detection system is to measure the difference between the background neutron count rate, due to spontaneous fission in the fuel material, and the count rate observed once the source is introduced, which is dominated by multiplication within the assembly. Based on the difference between these count rates, the fissile content of the assembly can be inferred, and this information can be used to determine if some fraction of the original fuel pins have been replaced with depleted uranium substitutes. The authors report that the system can detect the replacement of at least eight pins (3% of total mass). The ADVANTG code generates space- and energy-dependent weight-window bounds and biased source distributions based on approximate transport solutions that are efficiently generated by the Denovo 3-D discrete ordinates package. ADVANTG implements the Consistent Adjoint Driven Importance Sampling (CADIS) method for accelerating individual tallies and the Forward-Weighted CADIS (FW-CADIS) method for obtaining relatively uniform uncertainties across tallies over multiple regions and/or energy bins. The variance reduction parameters are generated in a format directly usable by standard versions of MCNP5 and MCNPX. In this work, the ADVANTG variance reduction parameter generator was applied to accelerate continuous energy MCNPX simulations of the {sup 252}Cf Interrogation with Prompt Neutron detection system for detecting the diversion of fuel elements from SNF assemblies. Variance reduction parameters generated with the existing version of ADVANTG actually slowed down tally convergence in all cases. The cause of the poor performance was found to be the lack of an induced fission source treatment in the fixed-source discrete ordinates calculations employed by ADVANTG. Because fission was treated as capture and not as a source, the importance maps generated by ADVANTG significantly underestimated the importance of thermal neutrons in and around the fuel elements. In order to obtain improved results, we developed an experimental implementation of a fission source outer iteration for the adjoint calculations. We used this prototype capability to generate new variance reduction parameters and found that the mean fission rates agreed well with those predicted by the conventional MCNPX simulations, as was expected. With these new parameters, speedup factors of 59 to 80 were obtained for the case with the background source, and factors of 17 to 24 were obtained for the cases with the interrogating source. These results demonstrate that a fission source treatment is needed to improve the effectiveness of ADVANTG in problems where the effects of induced fission are important. This includes many types of NDA problems that are relevant to safeguards applications. (authors)

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2019

Codes and Standards Update: February 2019

The goal of the DOE OE Energy Storage System Safety Roadmap is to foster confidence in the safety and reliability of energy storage systems. There are three interrelated objectives to support the realization of that goal: research, codes and standards(C/S)and communication/coordination. The objective focused on C/S is "To apply research and development to support efforts that refocused on ensuring that codes and standards are available to enable the safe implementation of energy storage systems in a comprehensive, non-discriminatory and science-based manner." The following activities support that objective and realization of the goal: (a.) Review and assess C/S which affect the design, installation, and operation of energy storage systems(ESS). (b.) Identify gaps in knowledge that require research and analysis that can serve as a basis for criteria in those C/S. (c.) Identify areas in C/S that are potentially in need of revision or enhancement and can benefit from activities conducted under research and development. (d.) Develop input for new or revisions to existing C/S through individual stakeholders, facilitated task forces, or through laboratory staff supporting these efforts. The purpose of this Codes and Standards Update is to support the above activities by providing information on efforts being conducted by U.S. standards developing organizations(SDOs)and other entities that are focused on ESS safety. The information is organized relative to the scope of each document in relation to ESS from the "macro to the micro"(e.g., from overarching covering considerable scope ,to installation specific, to ESS and then ESS components). Note that more macro documents are also likely to adopt by reference more micro documents.

25 ENERGY STORAGE↗

DOE OSTI2011

Feet on the potential energy surface, head in the pi clouds

This work presents explorations of the potential energy surface of clusters of atoms and of the interactions between molecules. First, structures of small aluminum clusters are examined and classified as ground states, transition states, or higher-order saddle points. Subsequently, the focus shifts to dispersion-dominated π-π interactions when the potential energy surfaces of benzene, substituted benzene, and pyridine dimers are explored. Because DNA nucleotide bases can be thought of as substituted heterocycles, a natural extension of the substituted benzene and pyridine investigations is to model paired nucleotide bases. Finally, the success of the dispersion studies inspires the development of an extension to the computational method used, which will enable the dispersion energy to be modeled – and the potential energy surface explored – in additional chemical systems. The effective fragment potential (EFP) method is described, as well as various quantum mechanical methods. An ab inito quantum mechanical study of 13-atom aluminum clusters is described. EFP studies of aromatic dimers are reported in which dispersion energy makes a significant contribution to the attraction between monomers. Theory and code development toward a means of computing dispersion energy in mixed ab inito-EFP systems are described.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2017

Department of Energy Air Emissions Annual Report Oak Ridge Reservation, Oak Ridge, Tennessee 40 Code of Federal Regulations (CFR) 61, Subpart H Calendar Year 2016

As defined in the preamble of the final rule, the entire DOE facility on the Oak Ridge Reservation (ORR) must meet the 10 mrem/yr ED standard.1 In other words, the combined ED from all radiological air emission sources from Y-12 National Security Complex (Y-12 Complex), Oak Ridge National Laboratory (ORNL), East Tennessee Technology Park (ETTP), Oak Ridge Institute for Science and Education (ORISE) and any other DOE operation on the reservation must meet the 10 mrem/yr standard. Compliance with the standard is demonstrated through emission sampling, monitoring, calculations and radiation dose modeling in accordance with approved EPA methodologies and procedures. DOE estimates the ED to many individuals or receptor points in the vicinity of ORR, but it is the dose to the maximally exposed individual (MEI) that determines compliance with the standard.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2014

Recent Advances in the Use of TRIPOLI-4 Monte Carlo Code for Radiation Protection and Shielding Calculations - Paper 47

TRIPOLI-4 is a general purpose radiation transport code. It uses the continuous-energy Monte Carlo method to simulate neutron, photon, electron and positron transport in three-dimensional geometries. The main application areas of TRIPOLI-4 code include radiation protection and shielding, fission reactor physics, nuclear criticality safety, fusion reactor design, and nuclear instrumentation. For the radiation protection and shielding calculations with TRIPOLI-4 code, miscellaneous radiation sources options, various variance reduction options, and many useful tally options are available. Perturbation calculations on material densities and nuclide concentrations are routinely used in radiation protection applications. Parallel calculations with TRIPOLI-4 are also easy to perform with a PC under the linux/unix OS. To help the users to get the feedback from their test runs during the input data preparation and adjustment and to analyze the intermediate and final results from their production runs, several user-interface tools have been introduced. By using some application cases in the fields of radiation shielding, radiation dosimetry, and gamma spectrometry, this paper summarizes and demonstrates some essential improvements and possibilities in the use of TRIPOLI-4 code on fixed source calculations. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

NASA NTRS1985

Secondary gamma-ray production in a coded aperture mask

The application of the coded aperture mask to high energy gamma-ray astronomy will provide the capability of locating a cosmic gamma-ray point source with a precision of a few arc-minutes above 20 MeV. Recent tests using a mask in conjunction with drift chamber detectors have shown that the expected point spread function is achieved over an acceptance cone of 25 deg. A telescope employing this technique differs from a conventional telescope only in that the presence of the mask modifies the radiation field in the vicinity of the detection plane. In addition to reducing the primary photon flux incident on the detector by absorption in the mask elements, the mask will also be a secondary radiator of gamma-rays. The various background components in a CAMTRAC (Coded Aperture Mask Track Chamber) telescope are considered. Monte-Carlo calculations are compared with recent measurements obtained using a prototype instrument in a tagged photon beam line.

Owens, A.↗

DOE OSTI2016

Gravity at the horizon: on relativistic effects, CMB-LSS correlations and ultra-large scales in Horndeski's theory

We address the impact of consistent modifications of gravity on the largest observable scales, focusing on relativistic effects in galaxy number counts and the cross-correlation between the matter large scale structure (LSS) distribution and the cosmic microwave background (CMB). Our analysis applies to a very broad class of general scalar-tensor theories encoded in the Horndeski Lagrangian and is fully consistent on linear scales, retaining the full dynamics of the scalar field and not assuming quasi-static evolution. As particular examples we consider self-accelerating Covariant Galileons, Brans-Dicke theory and parameterizations based on the effective field theory of dark energy, using the hi class code to address the impact of these models on relativistic corrections to LSS observables. We find that especially effects which involve integrals along the line of sight (lensing convergence, time delay and the integrated Sachs-Wolfe effect—ISW) can be considerably modified, and even lead to O(1000%) deviations from General Relativity in the case of the ISW effect for Galileon models, for which standard probes such as the growth function only vary by O(10%). These effects become dominant when correlating galaxy number counts at different redshifts and can lead to ∼ 50% deviations in the total signal that might be observable by future LSS surveys. Because of their integrated nature, these deep-redshift cross-correlations are sensitive to modifications of gravity even when probing eras much before dark energy domination. We further isolate the ISW effect using the cross-correlation between LSS and CMB temperature anisotropies and use current data to further constrain Horndeski models. Forthcoming large-volume galaxy surveys using multiple-tracers will search for all these effects, opening a new window to probe gravity and cosmic acceleration at the largest scales available in our universe.

79 ASTRONOMY AND ASTROPHYSICS↗