Test set of gaseous analytes at Hanford tank farms

DOE has stored toxic and radioactive waste materials in large underground tanks. When the vapors in the tank headspaces vent to the open atmosphere a potentially dangerous situation can occur for personnel in the area. An open-path atmospheric pollution monitor is being developed to monitor the open air space above these tanks. In developing this infrared spectra monitor as a safety alert instrument, it is important to know what hazardous gases, called the Analytes of Concern, are most likely to be found in dangerous concentrations. The monitor must consider other gases which could interfere with measurements of the Analytes of Concern. The total list of gases called the Test Set Analytes form the basis for testing the pollution monitor. Prior measurements in 54 tank headspaces have detected 102 toxic air pollutants (TAPs) and over 1000 other analytes. The hazardous Analytes are ranked herein by a Hazardous Atmosphere Rating which combines their measured concentration, their density relative to air, and the concentration at which they become dangerous. The top 20 toxic air pollutants, as ranked by the Hazardous Atmosphere Rating, and the top 20 other analytes, in terms of measured concentrations, are analyzed for possible inclusion in the Test Set Analytes. Of these 40 gases, 20 are selected. To these 20 gases are added the 6 omnipresent atmospheric gases with the highest concentrations, since their spectra could interfere with measurements of the other spectra. The 26 Test Set Analytes are divided into a Primary Set and a Secondary Set. The Primary Set, gases which must be detectable by the monitor, includes the 6 atmospheric gases and the 6 hazardous gases which have been measured at dangerous concentrations. The Secondary Set gases need not be monitored at this time. The infrared spectra indicates that the pollution monitor will detect all 26 Test Set Analytes by thermal emission and will detect 15 Test Set Analytes by laser absorption