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IMESAFR Overview
John Tatom; A-P-T Research, Inc.; Huntsville, AL, USA
Bill Evans; A-P-T Research, Inc.; Huntsville, AL, USA
Josh Hoffman; Institute of Makers of Explosives; Washington, D.C., USA
Clint Fritz; Nelson Brothers; Birmingham, AL, USA
Michelle Duncan; A-P-T Research, Inc.; Huntsville, AL, USA
Mary Robinson; A-P-T Research, Inc.; Huntsville, AL, USA
Keywords: IMESAFR, quantitative risk assessment, explosives safety
Abstract
The Institute of Makers of Explosives (IME) has sponsored the development of a quantitative
risk assessment (QRA) tool called IMESAFR (Institute of Makers of Explosives Safety Analysis
for Risk). This software has been developed to assess risks in situations where quantity-distance
(QD) cannot be met, and also for risk management.
The project has involved participation and collaboration from both U.S. and Canadian
government regulatory entities since the inception. The Bureau of Alcohol, Tobacco, Firearms
and Explosives (ATF), which regulates the storage of commercial explosives in the U.S., now
accepts risk-based variance requests using IMESAFR and the “Risk Bank” method. ATF is
evaluating moving to the use of numerical criteria for public individual and group risk. In
Canada, the Natural Resources Canada – Explosives Regulatory Division (NRCan-ERD) is using
IMESAFR for risk-based derogation requests when QD cannot be met. The Canadian Armed
Forces (CAF) are now also using IMESAFR as part of their Ammunition and Explosives Risk
Assessment Safety Case (AERASC) process.
IMESAFR v2.1 is the latest version of this software and contains an ammonium nitrate (AN)
module as well as the standard TNT-based algorithms for predicting explosion effects and
consequences. The program is anchored by data from recent Department of Defense (DoD) and
ATF test programs, and IME has also proposed a three-part test series.
1. Background
The IMESAFR project began, in discussion form, in 2004. Work on creating the QRA models
and actual software tool began in 2005.
1.1. Quantitative Risk Assessment - QRA
Although risk-based approaches to safety are not new and are in fact are commonplace when
dealing with some hazardous materials (e.g., chemical or nuclear), the use of QRA for explosives
safety is relatively new – especially in the U.S. An essential aspect of risk assessment is that the
