Publications

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On June 30, 2020, a 0.87 gram PETN charge being pressed in the Rapid Prototyping Facility (RPF), unexpectedly initiated, resulting in destruction of the pressing fixture but no injuries or facility damage. In response, the Safety Review Board (SRB) met on Aug. 13, 2020 and Oct. 1, 2020 to review information collected following the incident, consider likely direct causes, and form recommendations.

Controlling microscopic morphology of energetic materials is of significant interest for the improvement of their performance and production consistency. As an important insensitive high explosive material, triaminotrinitrobenzene (TATB) has attracted tremendous research effort for military grade explosives and propellants. In this study, a new, rapid and inexpensive synthesis method for monodispersed TATB microparticles based on micelle-confined precipitation was developed. Surfactant with proper hydrophilic-lipophilic balance value was found to be critical to the success of this synthesis. The morphology of the TATB microparticles can be tuned between quasi-spherical and faceted by controlling the speed of recrystallization.

The performance of energetic materials (EM) varies significantly across production lots due to the inability of current production methods to yield consistent morphology and size. Lot-to-lot variations and the inability to remake the needed characteristics that meet specification is costly, increases uncertainty, and creates additional risk in programs using these materials. There is thus a pressing need to more reliably formulate EMs with greater control of morphology. The goal of this project is to use the surfactant-assisted self-assembly to generate EM particles with welldefined size and external morphologies using triaminotrinitrobenzene (TATB) and hexanitrohexaazaisowurtzitane (CL-20) as these EMs are both prevalent in the stockpile and present interesting/urgent reprocessing challenges. We intend to understand fundamental science on how molecular packing influences EM morphology. We develop scale up fabrication of EM particles with controlled morphology, promising to eliminate inconsistent performance by providing a trusted and reproducible method to improve EMs for NW applications.

We recently developed a vacuum assisted micelle confinement synthesis for spherical microparticles of CL-20 with outstanding monodispersity. These microparticles are promising energetic material for explosive devices with enhanced and predictable performances. In this work, to facilitate further development and application of this synthesis, the particle growth process was monitored by in-situ dynamic light scattering measurements. The result was interpreted by a finite element model to obtain critical parameters. These parameters were then used to predict the behavior and product quality of batch synthesis under various operation conditions.

A series of sub-scale (10-gallon) drum experiments were conducted to characterize the reactivity, heat generation, and gas generation of mixtures of chemicals believed to be present in the drum (68660) known to have breached in association with the radiation release event at the Waste Isolation Pilot Plant (WIPP) on February 14, 2014, at a scale expected to be large enough to replicate the environment in that drum but small enough to be practical, safe, and cost effective. These tests were not intended to replicate all the properties of drum 68660 or the event that led to its breach, or to validate a particular hypothesis of the release event. They were intended to observe, in a controlled environment and with suitable diagnostics, the behavior of simple mixtures of chemicals in order to determine if they could support reactivity that could result in ignition or if some other ingredient or event would be necessary. There is a significant amount of uncertainty into the exact composition of the barrel; a limited sub-set of known components was identified, reviewed with Technical Assessment Team (TAT) members, and used in these tests. This set of experiments was intended to provide a framework to postulate realistic, data-supported hypotheses for processes that occur in a “68660-like” configuration, not definitively prove what actually occurred in 68660.