257 research outputs found
Performance of a uranium getter bed for removing deuterium from a flowing inert gas
The performance of a uranium trap as a means of removing tritium from an inert gas was measured for varying trap conditions, using deuterium (to represent tritium) in argon at room temperature. Performance was expressed as a purification factor, which is the ratio of deuterium concentration at the inlet to that at the outlet of the trap. Purification factors vary inversely with both the ratio of deuterium to uranium already contained in the trap and with the rate of flow of gas through the trap. Varying the inlet deuterium concentration had no apparent effect. (auth
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EDC-37 Deflagration Rates at Elevated Pressures
We report deflagration rates on EDC-37 at high pressures. Experiments are conducted using the Lawrence Livermore National Laboratory High Pressure Strand Burner (HPSB) apparatus. The HPSB contains a deflagrating sample in a small volume, high pressure chamber. The sample consists of nine, 6.35 mm diameter, 6.35 mm length cylinders stacked on end, with burn wires placed between cylinders. Sample deflagration is limited to the cross-sectional surface of the cylinder by coating the cylindrical surface of the tower with Halthane 88-2 epoxy. Sample deflagration is initiated on one end of the tower by a B/KNO{sub 3} and HNS igniter train. Simultaneous temporal pressure history and burn front time of arrival measurements yield the laminar deflagration rate for a range of pressures and provide insight into deflagration uniformity. These measurements are one indicator of overall thermal explosion violence. Specific details of the experiment and the apparatus can be found in the literature
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Deflagration Behavior of PBX 9501 at Elevated Temperature and Pressure
We report the deflagration behavior of PBX 9501 at pressures up to 300 MPa and temperatures of 150-180 C where the sample has been held at the test temperature for several hours before ignition. The purpose is to determine the effect on the deflagration behavior of material damage caused by prolonged exposure to high temperature. This conditioning is similar to that experienced by an explosive while it being heated to eventual explosion. The results are made more complicated by the presence of a significant thermal gradient along the sample during the temperature ramp and soak. Three major conclusions are: the presence of nitroplasticizer makes PBX 9501 more thermally sensitive than LX-04 with an inert Viton binder; the deflagration behavior of PBX 9501 is more extreme and more inconsistent than that of LX-04; and something in PBX 9501 causes thermal damage to 'heal' as the deflagration proceeds, resulting in a decelerating deflagration front as it travels along the sample
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Shielding experimental methods
Benchmark, parametric, and design-confirmation shielding measurements are made at the Tower Shielding Facility (TSF) in Oak Ridge. A powerful reactor (to 1 MW thermal) is used with spectral modifiers to provide neutron spectra close to those associated with the various parts of an LMFBR. The source strength allows measurements through shields of full reactor thickness using sensitive detectors. The detectors include spectrometers and dosimeters for both neutrons and gamma rays. A large exclusion area provides much flexibility in arranging shield assemblies to be studied
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Testing of explosives mixed with clay to determine maximum explosive content of non-reactive mixtures
This report contains a detailed description of the experiments conducted to demonstrate that debris from explosives testing in a shot tank that contains 4 weight percent or less of explosive is non-reactive under the specified testing protocol in the Code of Federal Regulations. As such it is a companion report to UCRL-ID-128999, "Program for Certification of Waste from Contained Firing Facility - Establishment of Waste as Non-Reactive and Discussion of Potential Waste Generation Problems.
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ODTX Measurements and Simulations on Ultra Fine TATB and PBX-9502
We measure the time to explosion of 12.7 mm diameter spheres of ultra fine TATB and PBX-9502 (95 wt% TATB, 5 wt% Kel-F 800) at 85.0, 92.5, and 98.0 percent of theoretical maximum density (TMD) in confined and unconfined configurations and at several elevated temperatures with the Lawrence Livermore National Laboratory (LLNL) One Dimensional Time to Explosion (ODTX) apparatus. Time to explosion data provide insight into the relative ease of thermal ignition and allow for the calibration of kinetic parameters. The measurements show that PBX-9502 is more thermally stable than ultra fine TATB, that unconfined samples are slightly more thermally stable than confined ones, and that lower density samples are more thermally stable than higher density ones. 'Go/no go' data at the lowest temperatures yield an experimental measurement of the critical temperature, which is the temperature at which an explosive can be heated indefinitely without undergoing self-heating and concomitant rapid and violent decomposition. Critical temperatures ranges for 12.7 mm diameter spheres of 98% TMD ultra fine TATB and PBX-9502 are 213-230 C and 234-239 C, respectively. Experimental data are modeled with ALE3D and kinetic parameters are determined. These kinetic parameters, when coupled with thermal property data, provide good prediction of the time to explosion
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LX-17 Deflagration at High Pressures and Temperatures
We measure the laminar deflagration rate of LX-17 (92.5 wt% TATB, 7.5 wt% Kel-F 800) at high pressure and temperature in a strand burner, thereby obtaining reaction rate data for prediction of thermal explosion violence. Simultaneous measurements of flame front time-of-arrival and temporal pressure history allow for the direct calculation of deflagration rate as a function of pressure. Additionally, deflagrating surface areas are calculated in order to provide quantitative insight into the dynamic surface structure during deflagration and its relationship to explosion violence. Deflagration rate data show that LX-17 burns in a smooth fashion at ambient temperature and is represented by the burn rate equation B = 0.2P{sup 0.9}. At 225 C, deflagration is more rapid and erratic. Dynamic deflagrating surface area calculations show that ambient temperature LX-17 deflagrating surface areas remain near unity over the pressure range studied
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SMALL-SCALE IMPACT SENSITIVITY TESTING ON EDC37
EDC37 was tested at LLNL to determine its impact sensitivity in the LLNL's drop hammer system. The results showed that impact sensitivities of the samples were between 86 cm and 156 cm, depending on test methods. EDC37 is a plastic bonded explosive consisting of 90% HMX, 1% nitrocellulose and binder. We recently conducted impact sensitivity testing in our drop hammer system and the results are presented in this report
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Program for certification of waste from contained firing facility: Establishment of waste as non-reactive and discussion of potential waste generation problems
Debris from explosives testing in a shot tank that contains 4 weight percent or less of explosive is shown to be non-reactive under the specified testing protocol in the Code of Federal Regulations. This debris can then be regarded as a non-hazardous waste on the basis of reactivity, when collected and packaged in a specified manner. If it is contaminated with radioactive components (e.g. depleted uranium), it can therefore be disposed of as radioactive waste or mixed waste, as appropriate (note that debris may contain other materials that render it hazardous, such as beryllium). We also discuss potential waste generation issues in contained firing operations that are applicable to the planned new Contained Firing Facility (CFF). The goal of this program is to develop and document conditions under which shot debris from the planned Contained Firing Facility (CFF) can be handled, shipped, and accepted for waste disposal as non-reactive radioactive or mixed waste. This report fulfills the following requirements as established at the outset of the program: 1. Establish through testing the maximum level of explosive that can be in a waste and still have it certified as non-reactive. 2. Develop the procedure to confirm the acceptability of radioactive-contaminated debris as non-reactive waste at radioactive waste disposal sites. 3. Outline potential disposal protocols for different CFF scenarios (e.g. misfires with scattered explosive)
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