NCJ Number
37777
Date Published
1976
Length
143 pages
Annotation
THIS DOCUMENT SUMMARIZES THE EFFORTS OF THE BROOKHAVEN NATIONAL LABORATORY AT TAGGING EXPLOSIVES AND BLASTING CAPS WITH A VOLATILE ELECTRONEGATIVE GAS TO ENABLE DETECTION IN BOTH CLOSE PROXIMITY AND REMOTE SCENARIOS
Abstract
THE USE OF SULFUR HEXAFLORIDE AS THE TAGGANT GAS WAS EXPLORED BY DETERMINING EXISTING AMBIENT LEVELS, EVALUATING BARRIER MATERIALS TO THE DETECTION OF THE GAS, SELECTING SUBSTANCES FOR THE ABSORPTION OF THE VOLATILE SULFUR HEXAFLUORIDE, DETERMINING HOW LONG SUCH ABSORBED SOURCES WOULD LAST, ASSESSING THE COMPATIBILITY WITH THE BLASTING CAP MANUFACTURING METHODS, EXPLORING DETECTION METHODS FOR SULFUR HEXAFLUORIDE, AND DEMONSTRATING THE FEASIBILITY BY DETECTING SOURCES IN SUITCASES. BACKGROUND LEVELS OF 0.5 TO 1.0 PART PER THOUSAND ONLY LIMIT DETECTION IN LARGE VOLUME SCENARIOS. ONLY TIGHTLY CLOSED MATERIALS (SUCH AS PAINT CANS) ARE EFFECTIVE BARRIERS TO THE SULFUR HEXAFLUORIDE. FLUOROPOLYMERS WERE FOUND TO BE THE MOST EFFECTIVE ABSORBERS OF SULFUR HEXAFLUORIDE HOLDING AS MUCH AS NINE PERCENT BY WEIGHT. PROJECTED INDICATIONS WERE THAT SUCH TAGGED SOURCES SHOULD LAST FOR 10 OR MORE YEARS IN SUITCASE SNIFFING SCENARIOS. MONITORING INSTRUMENTS COMMERCIALLY AVAILABLE DID NOT HAVE THE SENSITIVITY REQUIRED IN CONTINUOUS MODE SAMPLING. BUT INSTRUMENT DEVELOPMENTS AT BROOKHAVEN INDICATED THAT CONTINUOUS DETECTION DOWN AS TO LOW AS A FEW PARTS OF SULFUR HEXAFLUORIDE IN TEN TO THE FOURTEENTH PARTS OF AIR SHOULD BE POSSIBLE. OTHER ELECTRONEGATIVE COMPOUNDS WITH AT LEAST TWO ORDERS OF MAGNITUDE LOWER AMBIENT LEVELS ARE NEEDED FOR LARGE VOLUME DETECTION. (AUTHOR ABSTRACT)