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This document summarizes an incident where a large volume of explosive gas was detonated at the UH-Manoa's School of Ocean and Earth Science and Technology. This description is used as an example to teach lab safety.
This presentation is a part of the XCP- division seminar series and discusses computational techniques for high explosive hydrodynamics.
The year 2015 marks a turning point in China s plug-in electric vehicle (PEV) or new energy vehicle (NEV) industry, with an explosive growth in both productions and sales, following the gloomy period of 2009-2012. The PEV production in 2015 reached a record level of nearly 380,000 units, a 352 % increase from 2014, making China the largest PEV market in the world. For the potential implications on energy and the environment, it is worth studying the driving forces of China s PEV market and understanding its future trajectory and dynamics. The key findings of this report are listed in the following. Though controversial, the government monetary incentives have played a significant role to impel China to be the largest light PEV (191,100 units) market in the world. Chinese vehicle buyers appear more price sensitive on PEVs. Inexpensive low-cost micro electric vehicles are the most popular vehicle model in China s PEV market (38.9 % of the PEV market in 2015). In contrast, the premium or luxury vehicles are more popular in the gasoline vehicle segment. In fact, China is expected to be the largest premium car market in 2016. The PEV sales growth is primarily possible because of the young domestic private-owned auto manufacturers, which are mostly located in south China. Top-tier conventional vehicle automakers in China appear to be less proactive in the PEV market, based on market shares. This is in clear contrast to the U.S. market, where major automakers are generally the primary players in the PEV market. The PEVs produced by the domestic automakers are concentrated in the low-end market segment, while the high-end vehicle segment is dominated by the foreign brands. At present, the substantial market growth and government subsidies afford the domestic entrants to quickly gain profits in the low-end segment. The PEV consumers in China are very sensitive to the vehicle price, thus prefer the PEVs with cheaper prices after government subsidies, and care less about the driving quality and comfort. In contrast, most PEV consumers in the United States (U.S.) have higher incomes, view the PEVs as a high-status symbol, and care less about the vehicle prices, and therefore welcome the premium PEVs more in the U.S. The PEV financial subsidies by the Chinese government are divided into three stages based on the strategic directions and policies. In 2009 2012, government incentives concentrated on the public fleet vehicles, while excluding the individual consumers from the subsidies in most cities. In 2013 2015, comprehensive central/local government incentives were extended to all vehicle purchasers including the individual buyers in most cities, which was conducive to the phenomenal growth of the PEV sales. For years 2016 to 2020, monetary incentives are being phased out and will be substituted by other non-monetary incentives (such as the standards for Chinese Cooperate Average Fuel Consumption and New Energy Vehicle Credits) for the sustainable development of the PEV market. The PEV subsidy fraud has drawn attention by the central government, which prompts the government to be more prudent about monetary incentives. With the advantage of high acceptance in the PEV market and integrated EV charging infrastructure, the region with better economic development brings a more aggressive PEV roll-out plan to the municipalities who are more willing to solve the local urban pollution while keeping the automotive market in sustainable growth. On the one hand, the local automakers are offered abundant subsidies from the Chinese government to those who intend to help the Chinese automotive industry seize the industrial upgrading opportunity to transform its manufacturing sector, and they have taken most shares of the PEV market. On the other hand, facing the trade barriers, the foreign automakers have dominated the premium PEV sales in China, although their total market shares in the PEV market are much less than the domestic automakers. In diverse selectable alternative fuel vehicle technologies, China has put its focus on the PEV technologies for the technological modernization in the automotive industry; the research and development in fuel cell vehicle technologies in China is less competitive compared with other countries such as Japan and the U.S. With the demand of batteries from the PEV automakers, the Chinese EV battery industry is aggressively expanding. It has risks in excessive production capacity, and faces the challenges from the competitors from Japan and South Korea.
SCE (sensor comparison experiment) 1 through 4 consists of a series of four controlled above-ground explosions designed to provide new data for overpressure propagation. Infrasound data were collected by LLNL iPhones and other sensors. Origin times, locations HOB, and yields are not being released at this time and are therefore not included in this report. This preliminary report will be updated as access to additional data changes, or instrument responses are determined.
This presentation describes processes for explosive sites at LANL. Related career paths are also included.
HE ignition caused by shear localization is the principal concern for safety analyses of postulated mechanical insults to explosive assemblies. Although prompt detonation from shock is certainly a concern, insults that lead to prompt detonation are associated with high velocity, and correspondingly rare. For high-density HMX assemblies, an impact speed (by a steel object) of 400 m/s is needed to develop a detonation in a run distance less than 30 mm. To achieve a steady plane shock, which results in the shortest run distance to detonation for a given peak pressure, the impactor diameter must exceed 60 mm, and thickness approach 20 mm. Thinner plates and/or smaller diameter ones require even higher impact velocity. Ignitions from shear localization, however, have been observed from impacts less than 50 m/s in Steven tests, less than 30 m/s from spigot impact tests, and less than 10 m/s from various drop tests. This lower velocity range is much frequent in postulated mechanical insults. Preliminary computer simulations and analyses of a variety of such tests have suggested that although each is accompanied by shear localization, there are differing detailed mechanisms at work that cause the ignitions. We identify those mechanisms that may be at work in a variety of such tests, and suggest how models of shear ignition, such as HERMES, may be revised and calibrated to conform to experiment. We suggest combining additional experiments with computer simulations and model development to begin confirm or uncover mechanisms that may be at work in a specific postulated event.
Work on Magpie in the Theoretical Division has produced an important fundamental capability to LANL. Magpie now has the ability to predictively generate High Explosive (HE) equations of state (EOS). The code’s software design allows for quick and easy implementation of new EOS models. This will allow for advances in EOS modeling of not just molecular fluids, but the EOS of almost any substance. Magpie leverages powerful techniques of equilibrium statistical thermodynamics to build EOSs from microscopic level knowledge of atomic and molecular properties.
It is not known whether pristine (i.e. mechanically and thermally undamaged) PBX 9501 can transition from a deflagration to a detonation in realistic scenarios, with relevant charge masses and inertial and mechanical confinement. In order to place bounds on the behavior, a series of experiments was conducted in which a spherical PBX 9501 charge is center-ignited using a fiber-delivered infrared laser pulse. Charge diameter was varied from 1.5 in ch to 10 inch. Experiments were conducted in a “bare” (unconfined) configuration, and a confined configuration with 4 mm-thick stainless-steel hemispherical shells bolted together. In all eight experiments, the reaction exhibited a relatively benign pressure burst; no transition to detonation (DDT) was observed. Most of the explosive was unconsumed and recovered post-test. Confined tests demonstrated slightly greater violence than unconfined tests, as anticipated.
This project is an evaluation of the changes in the dimensional geometry of pressed explosive powder pellets when stored for prolonged periods under unmonitored storage conditions. Through the application of Structural Health Monitoring (SHM) techniques, questions to be answered by this investigation are what, if any, effect has the long-term storage of the pellets had on their physical attributes and, if changes have occurred, are the resulting differences of significant magnitude to affect the performance of the pellets. This resulting report includes a summary of the relevant background information, explanation of the SHM approach used to analyze the available data, presentation and discussion of the results, concluding remarks, and an accompanying appendix containing the MATLAB program developed for the project.
The Source Physics Experiment(SPE)explosions provide comprehensive ground truth information,and nearby recordings that are rarely available in typical monitoring scenarios. Here, we look for relationships with local and regional distance data to understand source and propagation effects in an effort to improve monitoring at a distance. We examine source spectral ratios, which can be measured to high precision by taking advantage of many SPE and independently operated stations, as well as the redundancy available from coda waves. Classical source models (Mueller and Murphy, 1971, MM71; Denny and Johnson, 1991, DJ91)predict the source ratios poorly; however, a hybrid model(MM71 with DJ91 cavity radii)performs better, and by varying cavity and elastic radii we obtain models that fit to within measurement precision. Based on this, the best prediction model for the SPE suite is the hybrid model with cavity radius decreased by 95%, and elastic radius decreased by 75%. This works best for mid-range scaled depths of burial (SPE-1, 2, 3, and 5). We do not guarantee transportability to other geologies,depth and scaled depth ranges. Finally, we observe a distinct spectral modulation at 6-9Hzthat is not predicted by classical models, and is most likely the result of interference of short period surface waves(Rg)with those produced by spallation of near surface layers.The same modulationis observed for compressional (P) and shear(S) waves at distance, indicating the origin of these waves as scattered Rg.The scattering process must be accounted for quantitatively when using distant signals to monitor treaty compliance over broad regions.
Three-dimensional geologic framework model of the P-Tunnel Complex and vicinity has been constructed for the Underground Nuclear Explosion Signature Experiment to address anisotropy of physical properties within the experiment medium. The P-Tunnel geologic framework model was constructed using EarthVision geologic modeling software by Dynamic Graphics, Inc. The model area covers 4.36 square kilometers and includes the entire P-Tunnel Complex. The model extends vertically from 2,004 meters above mean sea level, the highest land surface elevation in the model area, to 1,000 meters above mean sea level. The P-Tunnel Complex lies at an elevation of approximately 1,676 meters above mean sea level. The model incorporates data and information from more than 55 years of geological and geophysical studies in the P-Tunnel region, including surface and subsurface geology maps, tunnel construction drawings, a digital elevation model of the topography, and orthophoto imagery. The model consists of thirteen layers, with each layer defining a distinct stratigraphic interval with similar physical properties. Because no faults with significant offset are present within the model area, no faults are incorporated directly into the model. Small-offset faults and other prominent fractures mapped during tunnel construction, however, were digitized and gridded to produce fault and fracture planes that can be viewed within the model. The model has been exported as simple ASCII text files that define the model layers as either two-dimensional surfaces representing the tops of each model layer, or as three-dimensional volumes. The model was also exported as binary-STL files for three-dimensional printing.
Presentation covering Explosives Safety Program for LANL
The EPA has declared phase-out of Trinitrotoluene (TNT) a priority due to toxicity concerns. LANL and the Army Research Laboratory created a melt-castable next generation high performance explosive to replace TNT. They invented bis(1,2,4-oxadiazole)bis(methylene) dinitrate, or BOM, a higher-performing, safer replacement, which is 50% more energetic than TNT. BOM is less toxic to produce and use than TNT. Unlike competitors, BOM requires no performance-enhancing additives. BOM could replace TNT in a variety of civilian and military applications. BOM has been synthesized at the multi-kilogram scale.
This report summarizes analytical results and meets the requirements of Section 7.6.2 of Resource Conservation and Recovery Act (RCRA) permit (NEV HW0101) and Section B.20.i.2 of the RCRA Part B Permit Application for Waste Management Activities at the Nevada National Security Site Explosive Ordnance Disposal Unit.
After completing a study to ensure the simulation results were converged, several high resolution 3D Smoothed Particle Hydrodynamic (SPH) simulations of copper rods impacting a high explosive (LX14) target were performed. This was then formulated into an optimization problem: I wanted to find the optimum shape and location of a perturbation on the rod that would maximize its erosion after it left the target. The shape of the perturbation was modeled as a 2D Gaussian bump and parameterized by its location along the rod axis (z 0 ) and amplitude (A). The final mass of the coherent part of the rod as it leaves the target was used as a metric to represent the erosion of the rod, and the optimization was formulated to maximize this metric with respect to the aforementioned design variables. Due to the expensive nature of the high-fidelity 3D SPH simulations, a surrogate model needed to be chosen so that many function calls to the optimizer would be feasible. Thus, a strategic full factorial sampling plan was chosen to build a dataset, which consisted of 24 high-fidelity simulations. Two surrogate models, a third order polynomial regression model and a Gaussian Process Model, were analyzed using a 14%/86% test/train holdout technique. The root mean square and R2 score of the test set was used to determine the best model, and the third order polynomial regression model was chosen as the surrogate model. Finally, the Nelder-Mead Simplex and Basin-hopping optimization algorithms were implemented, and it was found that the two algorithms gave slightly different optimum values. Nelder-Mead gave an optimum point of [z* 0 ;A*] = [9:9;0:4] and Basin-Hopping gave an optimum value of x* = [z* 0 ;A*] = [9:2;0:1].
In 1996, negotiations between the National Nuclear Center of the Republic of Kazakhstan (NNC), the U.S. Defense Special Weapons Administration (DSWA) and the U.S. Department of Energy led to an agreement for a joint series of experiments at the former Soviet nuclear test site Semipalatinsk (STS). These experiments had a dual purpose: to close holes and tunnels originally created for the purpose of testing nuclear weapons, and to characterize explosive sources at a former nuclear test site. This report covers the recovery of legacy data from the experiments conduct in 1997 and 1998. Two teams collected data. Los Alamos National Laboratory (LANL), in collaboration with the NNC, collected the near-source (local) data out to approximately 20 km. Lamont-Doherty Earth Observatory (LDEO), with funding from Lawrence Livermore Laboratory (LLNL), also in collaboration with NNC, collected regional data, 200 – 1000 km distant, leveraging the KZ regional seismic network that LDEO had recently installed in collaboration with NNC. The two teams also worked together to some extent, regarding instrumentation and planning. This report primarily addresses the near-source data collected by the LANL/NNC team.
Reactive burn models represent a significant leap in high explosive (HE) modeling capability. The first generation of engineering models of HE detonation are called programmed burn models and they are largely based on the distance between a prescribed detonation point and each zone in a simulation. There have been many advancements to programmed burn models over the years and when the assumptions upon which they are based are met, a properly tuned programmed burn model can be highly accurate but if any of their assumptions is not met, as is the case for corner turning or weakly initiated HE burn, they will give the wrong answer. Reactive burn models represent an entirely new way of modeling HE burn. They use the local conditions of a zone – e.g. temperature, pressure or density – as calculated by a hydrocode to determine if and when the zone is going to detonate and if so, how rapidly. This difference opens up an entirely new set of capabilities for HE modeling. It makes it possible to accurately and predictively model phenomena like the effect of confinement and the formation of dead zones. Reactive burn models have seen sustained development effort at LANL for at least the last decade but several recent developments make it timely to transition reactive burn models from a research topic to a production tool. The main goal of this milestone is to facilitate and accelerate the adoption of reactive burn as a commonly available modeling option, with recommendations on the resolution that will be required and uncertainties associated with their modeling choices. To achieve this, we have performed verification, validation, and uncertainty quantification (UQ) assessments of AWSD and SURF/SURFplus in xRage and FLAG on a variety of different problems.
The analysis of seismic data for evidence of possible nuclear explosion testing is a critical global security mission that relies heavily on human expertise to identify and mark seismic signals embedded in background noise. To assist analysts in making these determinations, we adapted two compression distance metrics for use with seismic data. First, we demonstrated that the Normalized Compression Distance (NCD) metric can be adapted for use with waveform data and can identify the arrival times of seismic signals. Then we tested an approximation for the NCD called Sliding Information Distance (SLID), which can be computed much faster than NCD. We assessed the accuracy of the SLID output by comparing it to both the Akaike Information Criterion (AIC) and the judgments of expert seismic analysts. Our results indicate that SLID effectively identifies arrival times and provides analysts with useful information that can aid their analysis process.