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It is crucially important for comparison between reaction history experimental data and results of the high-performance weapons simulations that all types of uncertainty are correctly captured and propagated through the process. These notes are intended to formulate the problem, to provide a general overview, and remarks on the current stage of the research.
A graphics processing unit (GPU) has become a core technology for modern supercomputers. Applications that once ran on supercomputers are being forced to make significant changes to their designs to utilize these new machines. This paper introduces the concept of Thin-Threads as a method for history-based Monte Carlo transport applications on GPUs. The key principles behind Thin-Threads are light memory usage and communication and managing data race issues via atomics. We show that we can achieve a 10x speedup when moving from the traditional method to Thin-Threads on GPUs. Additionally, we demonstrate the viability of the Thin-Threads model at scale for GPU and CPU platforms.
LANL has an extensive history in the development and use of accelerators for defense, security, and stockpile stewardship.
This report describes the U.S. Nuclear Regulatory Commission’s (NRC’s) history with the licensing of non-light water reactors (LWRs). The focus is on regulatory policy and licensing issues that have arisen in the past so that NRC staff will be in a better position to deal with these matters in the future. It is not an objective to discuss in any detail the technology of non-LWR designs. Documenting the historical policy issues and licensing approaches is particularly important to NRC staff unfamiliar with non-LWRs and is an important incentive for the report. Hence, the report is written as a tutorial rather than as an historical archive. The subject is approached chronologically going from the early days of the Atomic Energy Commission to the formation of the NRC, then into the era when the regulatory structure newly developed for LWRs provided guidance for other types of reactors, and then into the era when policy was made specifically for advanced reactors including non-LWRs. This background provides the transition to current planning for future non-LWR licensing and policy.
With an intense work ethic, and high levels of devotion to their craft, seismologists continue to battle the elements and wrestle with complex logistics in their efforts to field instrumentation over the entire globe. We are fortunate to see data volumes accelerating in size, and quality continuing to improve; for example, universal timing issues can now be considered rare. However, instrument response issues are still common, and can hinder research that seeks to understand amplitudes of seismic wavefields. We are interested in using the accumulations of seismic data to develop models that will predict high frequency (0.2-20 Hz, and higher) signal amplitudes for explosion monitoring purposes over broad areas, which requires large data sets and extensive quality control. To identify response and station health issues, we have collected noise time histories for global seismic data, focusing on measurements near (but not restricted to) midnight to eliminate diurnal variations, and have manually determined time intervals that appear inconsistent with background behavior. We assign descriptive labels, but do not attempt to diagnose causes. We use these intervals to discard data. To date, we have examined 39,260 channels from 11,105 stations, heavily weighted toward IRIS holdings, dates through 2017 (depending on station, roughly the date we started our manual review), bands between 1 and 8 Hz, finding 24,733 anomalous time intervals. The great majority (90%) of these intervals appear to be shifts of constant offset, often bounded by times of known instrument changes, likely the result of poor documentation of response parameters at one of many stages between the field and the plotter. We hope these results can be of use to our colleagues, and would encourage community efforts to diagnose anomalous behavior, and fix poor responses. We also hope these results will support automation efforts, including application of supervised learning techniques.
This presentation will be presented at the NNSS FY 2020 SDRD Annual (Webex) Meeting scheduled for September 23–24, 2020. Wraparound PDV for Measuring the Impactor Velocity History in High-Hazard Plate Impact Experiments, STL-029-20, Year 1
This presentation covers the following: 1. Review of nuclear physics, 2. Fission weapons (WW2 and aftermath), 3. Weapon Effects, 4. Fusion physics, boost, and the hydrogen bomb, 5. Weapon development history – 1950’s, 6. Project Plowshare, 7. Modern weapons: the “Triad”, and 8. Thoughts on current situation and conclusions.
The presentation focus is on various aspects of nuclear engineering history, put together for a talk at UNM. A section of the talk also focuses on William 'Deak' Parsons.
The slides provide a history of the Manhattan project.
A historical talk covering the history of the Laboratory and major developments through the years.
This presentation provides an overview of key concepts in arms control, a history of nuclear arms control agreements, some of the contemporary challenges and opportunities in the field, a discussion of the process for negotiating arms control agreements, and updates on recent developments.
In this paper, we compare 4D seismic interpretations of CO 2 plume evolution with fluid flow numerical simulation results for the SECARB Early test at Cranfield, Mississippi. Historic pressure trends, oil and gas production rates and current CO 2 -EOR production data from the field were history matched and tuned model used for predictive simulations. For CO 2 -EOR operations the tuned model results showing CO 2 plume distribution and CO 2 first arrival (break-through) times in production wells were compared to the available field data. Reasonable matches were observed with breakthrough times. However 4D seismic interpretations of saturated region distributions and simulation results mismatch in some significant ways, likely showing limitations in 4D seismic interpretations for Cranfield. The tuned model then used to predict reservoir response and storage capacity in different field development scenarios. We compared hypothetical scenarios where the operator decided to transition into CO 2 injection without oil production (CO 2 -EORT) when oil production is not economical versus a scenario of continuing with CO 2 -EOR. Our results show that CO 2 -EOR can store more CO 2 and operations will last longer whereas if switched to CO 2 -EORT field has to be abandoned earlier because of out-of-area movement of the CO 2 plume. However, the amount of CO2 stored per year during the operational period is larger for CO 2 -EORT.
A chemical kinetics procedure for soot formation calculation is summarized. By importing Lagrangian hydrodynamic calculations, species history is consistently accounted for. Detonation product composition is assumed in region with the burnt high explosive (HE). Soot formation is calculated using the density and energy obtained in the hydrodynamics calculation of HE detonation. Ideal gas equation-of-state (EOS) with temperature-dependent specific heat is used in the HE product region. Sample calculations show reasonably-expected temperature and soot formation.
Ethanol has the achieved the greatest market share of all the alternative transportation fuels that have been researched, developed, and deployed in the US. There are multiple lessons to be learned from the history of ethanol adoption that can be applied to future fuels and products. Ethanol has replaced portions of gasoline in three main blend levels, with corresponding vehicles, equipment, benefits, and policies. The first is E10, which has replaced nearly all pure gasoline (E0) sold in the United States today (U.S. Energy Information Administration 2015). This was brought about through generations of policies that were motivated by multiple factors related to engine performance, energy security, health, air quality, and climate protection. Ethanol's high octane has been a consistent driver of the fuel because this enables higher performance engines. Early policies (1973-1979) were largely motivated by the desire to reduce dependence on petroleum sourced from members of the Organization of the Petroleum Exporting Countries, or OPEC. Fuel policy in the 1980s was largely in pursuit of promoting octane number enhancers that could replace lead. Criteria pollutant reduction was the overarching goal of actions taken from 1990 to 2005. From 2005 to the present, fuel policy has been largely motivated by energy security and climate protection goals. These policies were usually technology-agnostic and promoted multiple fuels and additives during each period. However, ethanol is the only fuel identified that is cost effective with qualities that enabled it to prosper in the policy environments of all four of these periods.The second market for ethanol is via 85% ethanol (E85). This fuel has the advantage of a greater concentration of ethanol but the disadvantage of not being compatible with regular gasoline vehicles. Instead, it can only be used in flexible-fuel vehicle (FFVs), which can use every blend level from E0 to E85. Therefore, much of the effort to increase E85 consumption has been aimed at incentivizing automakers to manufacture FFVs, drivers to purchase FFVs, and fueling stations to equip themselves to sell E85.The third, and newest, market through which ethanol is consumed is 15% ethanol (E15), which builds upon the E10 market to increase ethanol consumption by common gasoline vehicles. Efforts to create the E15 market consisted largely of testing vehicles and refueling equipment for compatibility, creating waivers to allow the use of E15, placing requirements on E15 retailers, and incentivizing retailers to equip themselves to purchase E15.
Recently, micropitting that occurred in a wind turbine gearbox has been used as a case study of the International Organization for Standardization technical specification ISO/TS 6336-22. This technical specification contains a proposed calculation of risk of micropitting in gear sets, in terms of a safety factor based on the ratio of the minimum to the permissible specific lubricant film thickness. This report summarizes the operational history of the micropitted gearbox for future case studies.
Atomic Power in Space II is a sequel to Atomic Power in Space (published by DOE in 1987). Beginning with a brief overview of the programs and systems developed through the late 1970s, Atomic Power in Space II traces the development and use of space nuclear power systems, including the missions and programs for which they were developed, to the present day. The history is written largely in non technical language so as to be useful to the general reader as well as the seasoned space nuclear professional.
The Monte Carlo method for radiation particle transport has its origins at LANL dating back to the 1940’s. The creators of these methods were Drs. Stanislaw Ulam, John von Neumann, Robert Richtmyer, and Nicholas Metropolis. Monte Carlo methods for particle transport have been driving computational developments since the beginning of modern computers; this continues today. In the 1950’s and 1960’s, these new methods were organized into a series of special-purpose Monte Carlo codes, including MCS, MCN, MCP, and MCG. These codes were able to transport neutrons and photons for specialized LANL applications. In 1977, these separate codes were combined to create the LANL Monte Carlo N-Particle (MCNP) radiation particle transport code. In 1983, MCNP3 was released for public distribution to the Radiation Safety Information Computational Center (RSICC). MCNP6.3 will be released late in 2021. Each year, LANL has ~100 MCNP new users and RSICC ~1250 new licenses distributed. This talk will review the Los Alamos history of the development of the modern Monte Carlo method and MCNP.