Guidance on Test Item Configurations for Insensitive Munitions System Safety Sympathetic Detonation Testing in Accordance with AOP- 4396

The Sympathetic Reaction test is used for Hazard Classification of munitions and Insensitive Munitions assessments. The results determine the munition's storage and handling procedures and are used in allotting investment funds for improving munition safety. The NATO Insensitive Munitions (IM) Sympathetic Reaction Custodian Working Group (SRCWG) met in Utrecht, Netherlands on Sept 17-18, 2018 to review and revise STANAG/AOP 4396 'Sympathetic Reaction, Munition Test Procedures'. The focus of this review was to update the test requirements, assess the technical metrics within the document for validity and applicability, ensure conformity with other NATO documents, and discuss national implementation procedures to ensure consistency of munition assessments. During discussions, it became apparent that there were discrepancies amongst the nations in selecting the quantity of munitions for the test, the test configuration, and the donor parameters. Additionally, while the volumetric requirement of 0.15 m³ (5.3 ft³) was undoubtedly adopted from the HC community (e.g. Orange Book / CFR-49), the technical rationale for this specific metric could not be ascertained.

Per STANAG 4396 Ed 2

• Section 8a states: "The test items should be in their storage/transport configuration, but in the smallest configuration (smallest individual package) offered. The test requires sufficient packages or articles to give a minimum total volume of 0.15 m³, with a minimum of one donor and two acceptor packages".
• Section 9b(1) states: "The volume of the stack must be at least 0.15 m³ minimum. If the volume of the donor and one acceptor package exceeds 0.15 m³, two acceptors are required, but three are desirable".
• Section 9b(2) states:?"Two tests shall be performed – one with confinement and one without".

The discrepancies were not only between the NATO member nations, but between the Hazard Classification (HC) community and the IM community as well. In general, each NATO member nation described their test set-up differently, such as: not applying the minimum volumetric requirement, utilizing inerts to meet the volumetric requirement, only using one acceptor, etc. The HC community noted that for HC assessment two tests are required, one in the Confined Configuration and one in the Unconfined Configuration; while the IM community noted that for IM assessment two tests are required, both in the Unconfined Configuration. These discrepancies could be an impediment to harmonization efforts between these communities.

The authors have investigated typical logistical configurations for munitions and found that the current volumetric requirement is appropriate as it applies to test item configurations. The technical justification is presented, along with a proposed guidance section to be incorporated into the STANAG/AOP, at the following SRCWG meeting in Brussels, BE in April, 2019. This paper discusses the technical justification for the volumetric requirement and the proposed guidance section.

Successfully implemented IM technology saves soldier lives' and their assets, and properly tested weapon systems improves safety at the at home in the load plants, as well as overseas in the battlefield

Reference:

[1] North Atlantic Council, STA

NAG 4396 - Sympathetic Reaction, Munitions Test Procedures, 2001, Ed 2.