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DOE/NNSA Insensitive High Explosive (IHE) Qualification and Testing
Lara D. Leininger, Jon L. Maienschein; Lawrence Livermore National Laboratory; Livermore, CA 94550
Daniel E. Hooks; Los Alamos National Laboratory; Los Alamos, NM 87545
Keywords: Insensitive High Explosive (IHE), Insensitive Munitions (IM), Deflagration-to-Detonation Transition
(DDT), Shock-to-Detonation Transition (SDT), Skid Test, Bullet Test
Abstract
Insensitive High Explosives (IHEs) are defined in Chapter IX of the Department of Energy (DOE) Explosive Safety
Standard (DOE, 2012). The qualification and approval process is specific to the DOE/National Nuclear Security
Administration (NNSA) nuclear deterrent mission, and it is completely separate from the Department of Defense
(DoD) and NATO Insensitive Munitions (IM) requirements.
The experimental series to qualify an IHE Material was changed by vote of the DOE Explosives Safety Committee
in 2015. The new criterion contains the following elements: 1. Deflagration-to-Detonation Transition (DDT); 2.
Shock-to-Detonation Transition (SDT); 3. Skid Test; and 4. Bullet Test. We discuss the background and technical
details of the four experiments.
Introduction
The DOE/NNSA routinely handles large, bare (uncased), charges of plastic-bonded explosives (PBXs), both for
high-explosive research and development and during the manufacture of nuclear warheads. A study by the NNSA
Office of Defense Programs’ Science Council (DOE/NNSA, 2015) recommends that all the PBX’s used in nuclear
weapons should be Insensitive High Explosive (IHE). That same study also noted expectations for IHE which
include improved safety throughout the life cycle of the weapon (in both DOE and DoD custody) and improved
production efficiencies. Nuclear warheads in production (either assembly or disassembly) present unique, and grave,
hazards. A set of criteria for qualifying an IHE to be used by DOE/NNSA must address these unique risks.
Currently, only TATB (2,4,6-Triamino-1,3,5-trinitrobenzene) and its formulations with Kel-F
(chlorotrifluoroethylene polymer) are qualified under the DOE Standard (DOE, 2012). Further, although the DoD
has protocols for the qualification of Insentive Munitions (IM), these requirements are for the munition system –
they are related to, but can be independent of, the high explosive used the warhead or rocket motor (DoD, 2014).
Therefore, the DoD IM requirements are not directly applicable to bare charges for DOE/NNSA.
Before the IHE qualification experiments were changed in 2015, the criterion by which an IHE was defined in the
DOE/NNSA consisted of eleven tests, articulated in the 1980’s by a small committee of subject matter experts at
Lawrence Livermore National Laboratory, under the assumption that the requirements would be adaptable and
constantly evolving based on the expert judgement of DOE/NNSA scientists. For example, one of the tests, the #8
cap test, had two significant shortfalls. First, it was selected because the group believed “super” insensitivity existed
when no commercial cap on the market would initiate the explosive at tap density. While this is a reasonable
argument, the committee did not anticipate that the definition of the cap would evolve in time and, in the case of the
#8, become more powerful. Second, the cap test was pulled from hazard division definitions (e.g. TB 700-2, DoD
2012, for HD 1.3 and HD 1.6), and directed at over-the-road transport threats which had no relevance to the
potential hazards in DOE/NNSA custody. Upon review, many of the other experiments had similar shortfalls; they
either addressed threats that were not relevant to nuclear safety (e.g. they addressed worker safety or over-the-road
transport, which are covered by DOE/NNSA high-explosive handling protocols and Department of Transportation
regulations), or they addressed ignition of the explosive material without speaking to the response of the material.
Early in the review to change the IHE qualification definitions, it was noted that Chapter IX of the DOE Explosive
Safety Standard (DOE, 2012) states: “IHE Materials are mass-detonable explosives that are so insensitive that the
