Systems Approaches in Propulsion and Explosives Toward Replacing Materials Such as Ammonium Perchlorate (AP), RDX, and TNT
SERDP, Weapons Systems and Platforms Program Area
Released October 27, 2016
Closed January 5, 2017
FY 2018
The objective of this Statement of Need (SON) was to investigate novel energetics formulations or engineering approaches in propulsion and explosives systems to meet current and future mission requirements across the Department of Defense, while eliminating ammonium perchlorate (AP), RDX, and TNT. Proposals addressing this SON should have utilized a systems approach whereby alternative ingredients were tested in appropriate formulations with coupled engineering solutions rather than as drop in replacements to meet explosive or propulsive performance. Material substitutions must have resulted in at least equivalent performance and less risk to the environment. This SON opened the trade-space for alternate propulsion and fragmenting warhead approaches that did not utilize AP, RDX, or TNT and still met the performance envelopes for current and future high-performance propellants (in terms of effect on faster time-of-flight and increased range, ballistic flexibility and service life) and high explosives without introducing toxic ingredients or degrading insensitive munitions performance.
Full proposals were required to include an assessment of the human health and environmental impacts of proposed ingredients, formulations, and byproducts. These proposals should have established a baseline lifecycle framework and identified the elements of a life cycle inventory that were already known, those that would have been investigated during the course of the project, and those that were beyond the scope of the proposed work.
Specifically, proposals were requested for either of the systems detailed below:
- An AP-free rocket motor system solution. Requirements for this system include a high performance tactical rocket motor that is notionally 10′′ diameter by 90′′ long, where length is measured from the forward dome of the motor pressure vessel to the exit plane of the nozzle, and is typically loaded with a solid aluminized composite propellant (ammonium perchlorate & aluminum) to maximize total impulse. Assuming a very high volumetric loading efficiency, differences in motor case design, and nozzle configuration, the propellant load-out for this hypothetical motor is theoretically in excess of 300 lbs, and potentially up to 315 lbs. Maximum theoretical delivered impulse is approximately 80,000 lbf-s. There is a desire to replace the current aluminized composite propellant solution with one that eliminates AP. It is requested that propulsion and/or formulation solutions be proposed for this 10-inch diameter form factor, delivering comparable total impulse. In propulsion solutions that deviate from traditional solid propellants, such as hybrid or liquids, ancillary components like tankage, valving, gas generators, etc., should be considered and discussed Expected propellant data for this notional approach will require the normal characterization (Table 1) in order to validate these assumptions.
- A Composition B Fragmenting Warhead Solution. A new melt-castable formulation coupled with a warhead design for a Composition B-loaded item must meet environmental, performance, IM, and producibility requirements. The proposal should be tailored to provide experimental assessments of performance, sensitivity, and initial environmental assessments of the proposed system solution (Table 2). Casing and formulation ingredients should be selected with a high emphasis on producibility (cost, processing/production methods, ESOH/lifecycle, etc.) and justified as such in the proposal.
Funded projects will appear below as project overviews are posted to the website.
Elimination of AP, RDX, and TNT from DoD weapon systems will substantially reduce the environmental impact of the system. Currently, perchlorate has the potential to leach into the groundwater throughout the entire life-cycle of the weapon system from manufacture of the energetic materials to the ultimate demilitarization of the system. The perchlorate ion is easily transported to groundwater due to its high solubility in water and weak affinity to soils. EPA studies show that perchlorate can impact normal thyroid activity by inhibiting iodine uptake even at low levels. RDX poses an environmental risk to groundwater beneath installations and ranges. If groundwater is contaminated with RDX from training or production operations, the surrounding community may be exposed to RDX through drinking water. Multiple state and federal regulations set limits for RDX in groundwater and drinking water to protect these communities. Any violation of these limits may require costly range remediation and groundwater cleanup and have led to curtailment of testing and training activities at ranges. Several reports have also found RDX to cause neurotoxicity and convulsions from high oral exposures. Synthesis of TNT results in significant waste streams including “red water,” a reactive waste often composed of inorganic salts and nitroaromatics. TNT is a hazard and health risk to workers at ammunition plants and it is readily absorbed through the skin and can also represent an inhalation risk.
AP, RDX, and TNT are ubiquitous within the DoD. AP, TNT and RDX have been identified as environmental risks due to mobility in groundwater from contaminated surfaces. TNT also presents an occupational health hazard due to dermal and inhalation issues. Program Managers, installations and, most importantly, Warfighters across all services would benefit from sustainable, next generation explosive and propulsion formulations that do not require AP, RDX, or TNT. Elimination of AP, RDX, and TNT will reduce environmental issues throughout the lifecycle, from manufacture of the material to demilitarization operations.
Propulsion. There are currently no known viable alternatives for AP as the main oxidizer in solid rocket propellants. Although alternative oxidizers exist that do not contain perchlorates, the alternatives suffer from cost, availability, stability, and performance issues that prevent them from being viable alternatives. In order to identify a viable replacement, individual tactical missile systems requirements must be considered due to the wide range of performance requirements of the entire U.S. tactical missile arsenal.
Composition B. Composition B is a melt-castable high explosive formulation composed of RDX and TNT. Research and development efforts to produce RDX and TNT alternatives have resulted in limited transitioned products to the industrial base. Most alternatives suffer from environmental, cost, availability, stability, and performance issues which prevent them from being viable alternatives.
The cost and time to meet the requirements of this SON are at the discretion of the proposer. Two options are available:
Standard Proposals: These proposals describe a complete research effort. The proposer should incorporate the appropriate time, schedule and cost requirements to accomplish the scope of work proposed. SERDP projects normally run from two to five years in length and vary considerably in cost consistent with the scope of the effort. It is expected that most proposals will fall into this category.
Limited Scope Proposals: Proposers with innovative approaches to the SON that entail high technical risk or have minimal supporting data may submit a Limited Scope Proposal for funding up to $200,000 and approximately one year in duration. Such proposals may be eligible for follow-on funding if they result in a successful initial project. The objective of these proposals should be to acquire the data necessary to demonstrate proof-of-concept or reduction of risk that will lead to development of a future Standard Proposal. Proposers should submit Limited Scope Proposals in accordance with the SERDP Core Solicitation instructions and deadlines.