into the design and construction of PCAPP and BGCAPP: DAAMS and MINICAMS. For example, the PCAPP facility has incorporated 137 DAAMS into the air monitoring system, typically with adjacent MINICAMS (Waybright, 2011).

Briefly, DAAMS preconcentrate air samples for preset sampling intervals using a sorbent filled-tube or sample loop, followed by agent desorption and gas chromatography-mass spectrometry (GC-MS) characterization. Typically, samples are preconcentrated for an 8-hr collection time and a full analysis is performed within 24 hr to provide archival analytical results. In contrast, MINICAMS utilize cycled GC measurements to provide near-real-time (NRT) analyses that take approximately 5 to 15 min. Depending on the specific contaminated matrices expected during agent processing, changeover, or closure activities, the specific protocols used primarily conform with those prescribed by the U.S. Environmental Protection Agency.

The samples derived from the anticipated waste streams, including from plant decommissioning activities, vary widely in their physical characteristics (for instance, their state and volume and type of matrix) and the agent contamination spatial resolution desired. Although DAAMS and MINICAMS technologies for vapor analyses have been demonstrated to be reliable, they do not provide good spatial or temporal resolution and are not particularly well suited for the direct analysis of agents in condensed-phase wastes and in occluded or potentially occluded volumes (see Box 3-3).

Recent advances in analytical technologies, as described below, are anticipated to complement existing agent monitoring strategies and may improve workplace and environmental safety. They provide the ability to detect agent contamination directly for a variety of matrices as well as agent in the gas phase, potentially providing high spatial resolution and rapid temporal assessments of agent contamination. These features are particularly relevant for more efficient and timely characterization of wastes during the agent processing and agent changeover phases of demilitarization operations. The ability to rapidly scan protection gear (demilitarization protective ensemble (DPE) suits) as workers exit Class A areas, where the suits may have been contaminated by exposure to chemical agents, could enhance worker safety while greatly reducing the time spent in decontamination and transition. In addition, the committee envisions that the application of these advanced technologies during plant decommissioning (closure) activities could reduce the time required for this phase of the project, yielding significant cost savings. Finally, the spatial resolution and rapid temporal response of the new analytical methods described below might prove to be an invaluable asset in dealing with unanticipated events such as an agent release, facilitating the tracking of any vapor releases to their source.

Two recently developed surface measurement technologies based on mass spectrometry ambient ionization techniques have been commercialized and found widespread application: direct analysis in real time (DART) (Cody et al., 2005) and desorption electrospray ionization (DESI) (Takáts et al., 2004). These are illustrated in Figures 4-1 and 4-2 and discussed in greater detail below. DART, DESI, and related techniques (Harris et al., 2011) allow direct sampling and analysis of a wide variety of liquid or solid matrices and produce high spatial resolution information to localize the target analytes. DAAMS and MINICAMS provide information about time-averaged agent concentration levels in the air or from the vapor headspace of samples in enclosed spaces. Such information represents indirect measurements of where the contamination is

The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement