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The enclave model for research and manufacturing enables stronger collaboration and more agile responses in support of national security priorities.
Lawrence Livermore National Laboratory supports the nation’s nuclear deterrent through the Stockpile Stewardship Program. Research into energetic materials—materials with high amounts of stored chemical energy that can be released rapidly—is critical to both conventional and nuclear defense systems. Livermore established the Energetic Materials Center (EMC) in 1991 to provide needed research and development (R&D) capabilities for the Laboratory’s nuclear weapons program, develop strategic partnerships with the Department of Defense (DOD), transition technology from Department of Energy national laboratories to commercial industries, and advance energetic materials science in partnership with universities. With the evolution of the national security landscape since the EMC’s founding at the end of the Cold War, Livermore’s approach to energetic materials research and manufacturing has evolved.
In recent years, Lawrence Livermore has developed and deployed an enclave model to encompass both the design agency, such as Livermore, and production agencies into one highly collaborative model of research, development, and production. The Polymer Enclave (see S&TR, November/December 2021, Polymer Production Enclave Puts Additive Manufacturing on the Fast Track) enables more frequent and direct communications between Lawrence Livermore and national security enterprise (NSE) partners, particularly the Kansas City National Security Campus, to cross-educate staff and address challenges early in the design or production process.
Livermore’s second enclave, the Energetic Materials Development Enclave Campus (EMDEC), launched in 2022 to strengthen manufacturing partnerships among Lawrence Livermore and Los Alamos national laboratories and production agencies, in particular the Pantex Plant (Pantex) near Amarillo, Texas. EMDEC further enhances Livermore’s technical capabilities in the field of energetic materials and enables researchers to develop more predictable and reliable solutions to manufacturing science challenges, in alignment with the Laboratory’s national security mission. The enclave also promotes future Laboratory development of manufacturing capabilities for the broader NSE. Located at Livermore’s main and experimental test sites, EMDEC encompasses planned, emerging, and existing energetic materials facilities plus new resources such as the Facility for Advanced Manufacturing of Energetics (FAME).
Designing Productive Partnerships
EMDEC deploys capabilities and processes to create new energetic molecules through chemical synthesis, formulate the energetic materials into plastic-bonded explosives (PBXs), and further transform the material into engineered high-explosive (HE) components. The HE components are then assembled into test articles for evaluation and dynamic testing. These integrated processes enable a self-sustained design–fabricate–test cycle necessary for HE development and qualification.
Creating—developing, synthesizing, and formulating—new energetic materials at the design stage and then manufacturing energetic materials at the production scale are two markedly different processes. Regular communication between the two efforts is needed to avoid delays in transitioning to production. Scientists and production engineers tend to think differently about the approaches to and parameters for developing new components, and this gap can create challenges for both sides if it remains unbridged. Alex Gash, EMC deputy director and the Strategic Deterrence lead for HE facilities and materials infrastructure, characterizes the differences between design and production agencies as a matter of scale. “At the material design stage, Livermore researchers conduct materials synthesis work at small scales, say around 10 to 100 liters,” says Gash. “Production agencies, however, are operating at much larger scales, on the order of 4,000 liters or more, and the parameters that influence the processes to produce materials at scale can be vastly different from those at smaller scales.”
The enclave model is intended to bridge these gaps in communication and understanding. Robert Maxwell, the program director for materials and manufacturing transformation who oversees all of Livermore’s enclaves, says, “Our enclave model is an excellent way to strengthen our partnerships and reenergize them. R&D efforts need to be translated into actual production processes, and R&D needs to be closer to the design and certification community to achieve that goal. We might come up with a brilliant idea at Livermore, but if we don’t start collaborating with the production agency partners early enough, we can go too far down the road without understanding the consequences of the regimes they have to work with.”
Incorporated into the enclave model are regular calls and frequent visits between EMDEC at Livermore and Pantex in Texas. In-person visits and exchanges allow the manufacturers to observe firsthand the design process and understand the rationale behind the small-scale R&D approach. Conversely, visits by Livermore staff to Pantex enable scientists and weapon designers to walk the production floors and observe what is practically needed to produce energetic materials at scale. Monty Cates, senior director for explosive technology operations at Pantex, has worked in explosives at the production agency for 33 years. Cates has observed the benefits that the EMDEC partnership has provided to the production process. “The improvements in communication have made a big difference in how Livermore and Pantex meet the needs of the NNSA (National Nuclear Security Administration) mission,” says Cates. “What excites me the most is that we’re able to take items from the concept stage to a working concept at Livermore and EMDEC and put those ideas into practice at Pantex in a much quicker timeframe than before.” According to Cates, EMDEC and the enclave model have enabled both Livermore and Pantex to become more agile. Design and production processes that took 10 years to complete in the past are on track for completion in roughly half the time.
Parallel Processes
Despite the relatively recent initiation of EMDEC, April Sawvel, a materials chemist and deputy for HE facilities and materials infrastructure at Livermore, has already seen signs of improved partnership and better communication. “Our relationship with Pantex and other partners has been very positive to date, and future plans leverage those relationships and the capabilities that we have already started developing together,” says Sawvel. The partnership has helped avoid siloed work that can occur in programs involving large numbers of people and many different teams. Cates adds, “One of the reasons this partnership has been so successful is that the principal investigators have been able to set the pace, work the problem, and develop solutions. The people who are most interested in seeing this partnership’s outcomes move forward are the ones working the problem together.”
Livermore and Pantex have installed identical equipment in each of their facilities so that the same operations can be run in the same environments and with the same parameters. Both agencies collect data through in situ diagnostics on the manufacturing processes and performance results from energetic materials testing. “This data feeds into our efforts to develop and implement a more predictive model that links energetic materials properties to performance so we can design more innovative energetic materials that will achieve desired properties,” says Sawvel. Maxwell is optimistic about the role EMDEC will play in national security. “EMDEC has tools in development that will allow us to constantly change different processing variables and produce appropriately tailored materials for controlled engineering and physics experiments to inform our modeling efforts, which will subsequently make us more responsive in the future,” says Maxwell.
Beyond the benefits of increased communication and engagement, interaction with Pantex has helped Lawrence Livermore appreciate the difference in the HE infrastructure, policies, and procedures between the design agency development work and production agency manufacturing. Pantex has played an important role in guiding the Laboratory and training workers on the additional safety standards and practices needed for production operations through worker training. Kyle Sullivan, a materials scientist in Livermore’s Physical and Life Sciences Principal Directorate, says, “Because we are dealing with an explosives work environment, and because we’re now doing more than our past small-scale operations, we had to make sure our explosives-rated machines were in a safe environment to operate and that our personnel have the training to do their work without undue risk of hazard or injury.” An explosives environment is a space in which explosive material might interact with other potential hazards in the area, such as equipment, explosive dust or vapor floating through the air, or exposed electrical circuitry. To ensure a safe manufacturing environment, no electrical circuits can be exposed, utilities must be appropriately plumbed, and pressure levels must be monitored and maintained to prevent explosive materials entering workspaces.
Improving PBXs Acoustically
With national security needs for HE and energetic materials evolving from Cold War concerns to international terrorism and rogue state threats to current and future priorities, the EMDEC team is a critical element in Livermore’s efforts to rise to the new challenges. Efforts include adapting existing energetic materials research to new technologies. This is the case for PBXs, in which HE materials such as triaminotrinitrobenzene particles are bound together with a synthetic polymer. In the legacy process for PBXs manufacturing, the as-synthesized explosive powder is coated with the polymer binder, creating a composite through the formulation process. The resulting granular material is pressed, typically at elevated temperatures, to produce a solid billet of PBXs. The billet is subsequently machined to yield the final component.
Researchers at EMDEC are developing a better understanding of PBXs while also modernizing the technology to make the explosives. “We’ve seen many advancements in adjacent technical fields as far as the equipment used to manufacture these materials, new modes of mixing, and different ways of synthesizing materials,” says Gash. “For EMDEC, we want an energetic materials production capability going forward that is adaptable to further modernization and can incorporate many of the new technologies developed in the past few decades.”
PBXs and other materials for conventional weapon design do not always translate into the same materials for nuclear design, however. For the W87-1 Modification Program (see S&TR, December 2022, W87-1 The Modification that Invigorated an Enterprise) and the W80-4 Life Extension Program (see S&TR, October/November 2018, Extending the Life of a Workhorse Warhead), the energetic materials required are different from those of nonnuclear weapons, as is the design process. “We have much tighter performance and engineering requirements to make the materials, and we have to design and manufacture them very precisely,” says Gash.
To meet these design and manufacturing challenges, EMDEC needed modernized capabilities, tools, and equipment. FAME opened in July 2023 and represents some of EMDEC’s emerging capabilities. Sawvel says, “FAME is the first facility at EMDEC to focus entirely on the development of new technologies for the manufacturing of energetic materials at a demonstration scale.” In addition to developing new manufacturing technologies, the incorporation of in situ diagnostics across multiple platforms enables researchers to gather real-time feedback on what is happening to the materials as they are being processed.
FAME’s main areas of focus include additive manufacturing for explosives and advanced formulation of energetic materials. “FAME is intended to be a one-stop shop for testing and scaling up the next generation of manufacturing concepts for explosives,” says Mike Grapes, a scientist at FAME and the lead for HE additive manufacturing development. Taking already synthesized molecules, scientists at FAME formulate those molecules with a binding agent to make the materials safer to handle and to give them mechanical properties that allow the molecules to be pressed or extruded into desired structures. “We don’t work with explosives in their pure molecular form because they are hard crystals, similar to salt or sugar,” says Grapes. “Pressing sugar crystals into a material that will have significant strength is difficult. However, by adding a polymer binder we derive an explosive with much better mechanical properties.”
Some of the most advanced capabilities at FAME are ResonantAcoustic® Mixing (RAM) and 3D printing. RAM was developed by Resodyn Mixers and is being used to develop new processing techniques for HE materials including the mixing of pastes for 3D-printing applications, new methods for the fabrication of PBX prill, and the particle size modification, or milling, of HE powders. In the versatile RAM platform, different 3D-printing vessel types can be used, enabling materials processing from the mixing of solids to the milling of particles. The technology can yield different sizes and shapes of materials in quantities from as little as 0.1 grams to upwards of 420 kilograms. Scale-up of this technique to determine its viability for production levels through EMDEC with Livermore’s partners at Resodyn, Los Alamos National Laboratory, Pantex, and DOD is part of future plans for EMDEC research.
RAM technology also supports the enclave’s goals by mixing materials including powders and liquids to form viscous materials such as slurries and pastes. Livermore scientists use these RAM-produced pastes, similar in viscosity to cake icing or toothpaste, to 3D print energetic materials. Comparable to direct ink writing 3D printing in Livermore’s Polymer Production Enclave, FAME 3D prints solid shapes (rather than the lattices of polymer 3D printing) of explosive materials and binding materials on a scale of kilograms. After printing is complete, the binder is cured, and the piece hardens.
While different sizes of the RAM equipment are installed, operational, and available for HE processing across EMDEC, Livermore scientists have traveled to Pantex to help the production agency set up and operate their equivalent RAM machine. As part of the enclave model, Livermore and Pantex have been sharing and testing procedures for different materials. In spring 2024, a group of Pantex scientists and engineers traveled to Livermore to observe new design and production processes.
A More Agile Process
Additive manufacturing via 3D printing is common in many areas of scientific research. However, to design, develop, and deploy 3D printers capable of printing explosive material while operating in an explosive production environment is unique—so unique that such printers exist in only two locations: FAME and Pantex.
Two 3D printers in FAME can additively manufacture energetic materials. One machine is a large format printer that Grapes and others at Livermore designed and built using a commercial-off-the-shelf motion system and other equipment from the Laboratory. The second 3D printer was designed by a commercial vendor in consultation with Livermore and Pantex and designed to meet the more stringent electrical safety requirements for an HE production environment. The equipment is capable of printing up to four different materials using a tool changer, enabling Livermore designers to push the boundaries of additive manufacturing technology. “We’ve barely scratched the surface of what this machine can do,” says Grapes.
Because the two printers are identical, both Livermore and Pantex can perform the same tests and produce the same components in different locations and generate the same results. Thus far, both design and production agencies have used these identical machines to fabricate the same articles. “We talk regularly with our partners at Pantex as we’re conducting these tests,” says Gash. “When we develop a process or print a particular explosive component, they’re doing the same thing on the same equipment in Texas. The enclave model increases efficiency and will enable more rapid weapons design-to-production process transfers than have occurred in the past.”
Furthermore, the enclave model is ensuring a more agile process. FAME is researching the use of production process data for quality assurance inspections onsite rather than sending produced pieces elsewhere for approval. The additive manufacturing equipment at FAME serves as a diagnostics test bed for sensors to measure all aspects of the process. The goal is to feed these diagnostics into a digital reconstruction of the part after printing, which will enable Livermore to virtually inspect and assess whether the parts meet the production requirements. In addition, physics codes simulate performance to determine if the part will act as intended.
The Future of Energetic Materials
While EMDEC is growing with the 2023 launch of FAME, the EMDEC team is already thinking ahead to develop the capabilities needed to meet evolving security threats. Sullivan says, “We’re in the process of identifying cross-cutting technologies, strategies, and lessons learned from the engagements with Pantex and our other partners and from the technical areas of overlap applicable to a variety of uses.” Such technologies and strategies include how in situ measurements of processes could be used to accelerate development of materials and how new modeling approaches such as machine learning or artificial intelligence can be used at multiple stages to accelerate these approaches.
The EMDEC team is seeking to develop and build new facilities. The EMDEC eXpansion (EMDEC-X) is planned at Livermore’s experimental test site with the intent to address future national security needs in advance. Sawvel says, “For EMDEC and its expansion, we aim to have a firm understanding of the science, chemistry, and performance of the materials we work with so we can make faster material selections in the future.” Plans for EMDEC-X include increasing the scale of work being tested and proven at FAME; expanding the scope to develop, test, and produce novel energetic materials by pushing the boundaries of the new facilities’ capabilities; and fostering more collaborative workspaces for the enclave partnership across the NSE to include Los Alamos and Sandia national laboratories as well as the UK’s Atomic Weapons Establishment. “The EMDEC teams have accomplished so much, and we will not slow down,” says Lara Leininger, Energetics Materials Center director. “The projects executed in this model have been immediately impactful to our mission. Reports such as the NNSA Energetics Enterprise Vision 2040 highlighted the need for increased capacity, capability, partnership, and academic engagement in energetic materials research. Executing EMDEC-X plans is key to achieving that vision for the nuclear security enterprise, and I cannot wait to see what comes next.”
Agility, responsiveness, and predictability are key priorities for EMDEC now and in the future. “We’re working to solve highly challenging chemistry, material, and engineering problems. When we were doing this work 30 years ago, we didn’t have the tools and capabilities to have as clear an understanding of what happens in the process,” says Gash. “In a sense, we get another bite at the apple now because we have the opportunity to work with excellent partners in a collaborative model that fosters innovation and helps us all achieve our mission goals.”
– Sheridan Hyland
For further information contact Alex Gash (925) 423-8618 (gash2 [at] llnl.gov (gash2[at]llnl[dot]gov)).
