Discrimination of phosgene from cyanogen chloride in recovered chemical munitions using tagged neutron interrogation with high-resolution gamma-ray spectroscopy

Journal Article · 24 November 2022 · Applied Radiation and Isotopes

DOI: https://doi.org/10.1016/j.apradiso.2022.110578 · OSTI ID:1957622

Bucher, Brian M.  ^[1]; Seabury, Edward H.  ^[1]; Hix, Jay D. ^[1]; Krebs, Kenneth M. ^[1]; Wharton, C. Jayson  ^[1]; McConchie, Seth M. ^[2]; Hausladen, Paul A. ^[2]

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1. Idaho National Laboratory (INL), Idaho Falls, ID (United States)
2. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

The Associated Particle technique has recently been utilized with a germanium-based high-resolution $$\gamma$$-ray spectrometer and assessed for its capability to improve field identification of recovered chemical warfare (CW) materiel through prompt gamma-ray neutron activation analysis (PGNAA) measurements. An accurate chemical identification is necessary for the safe handling, destruction, and disposal of such hazardous items. A particularly challenging pair of CW agents commonly found in recovered munitions are phosgene (CG) and cyanogen chloride (CK), which have two of three elements in common, i.e. chlorine and carbon, but differ in the third being either oxygen or nitrogen. The detection of both latter elements is complicated by high oxygen concentration in the field environment which interferes with the small signal produced from the chemical agents. The matter is further complicated by the precautionary field practice of overpacking recovered munitions with vermiculite in larger steel multiple round containers (MRCs), which places additional oxygen-rich material around the munition while further attenuating an already weak signal emitted from the munition center. Here, this work reports quantitative results from realistic field measurements of CG and CK simulants in mock 4.2-inch mortar rounds overpacked with vermiculite in a large MRC. Results obtained with the AP technique are compared to those obtained with the traditional PGNAA approach for both overpacked- and bare-munition measurements. The AP technique is shown to provide a much more confident discrimination between the two chemicals, particularly for the more challenging field-relevant overpacked measurements, where a significant gain in sensitivity to all the key elements chlorine, carbon, nitrogen and oxygen is achieved.

• Research Organization: Idaho National Laboratory (INL), Idaho Falls, ID (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: U.S. Army Chemical Materials Activity (CMA); USDOE Laboratory Directed Research and Development (LDRD) Program
• Grant/Contract Number: AC07-05ID14517
• OSTI ID: 1957622
• Report Number(s): INL/JOU-22-68565
• Journal Information: Applied Radiation and Isotopes, Journal Name: Applied Radiation and Isotopes Journal Issue: February 2023 Vol. 192; ISSN 0969-8043
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English