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3
Agent Monitoring Practices for Waste Generated
at BGCAPP and PCAPP
In this chapter, the committee briefly describes plans for the overall monitoring of
waste streams expected to be generated at the Blue Grass Chemical Agent Destruction
Pilot Plant (BGCAPP) and the Pueblo Chemical Agent Destruction Pilot Plant (PCAPP)
and uses this as a basis for identifying opportunities to employ new ambient ionization
surface-sensitive mass spectrometric techniques that offer potential benefits at these two
Assembled Chemical Weapons Alternatives (ACWA) pilot plants. The committee
recognizes that plans for operating these facilities are well under way and that any
implementation of new technology may require time for adaptation and procedural
vetting, etc. Given these considerations, surface measurement technologies may most
likely be utilized during the later stages of operations, particularly during facility closure.
The committee wishes to point out that in examining the applicability of the new
technologies discussed in this report, it is not calling into question the current monitoring
protocols planned for these facilities. These have proven to be safe and effective during
nearly two decades of chemical agent disposal campaigns at other chemical
demilitarization facilities. Rather, the question is whether the new techniques could offer
capabilities that beneficially augment the present techniques and perhaps lead to a
reduction in the duration of the overall schedule.
This chapter is intended to identify monitoring opportunities and challenges.
Chapters 4 and 5 address the suitability of the new ambient ionization mass spectrometric
techniques to address those challenges. Several potential scenarios are presented in this
chapter, where new measurement capabilities might facilitate faster, safer, or more
efficient agent disposal and closure operations.
WASTE ANALYSIS OVERVIEW
Chapter 2 presented an overview of the process flow plans for PCAPP and
BGCAPP. This chapter addresses the plans for monitoring and analysis of those
processes and the waste streams they will produce. This is not a comprehensive review
because this subject was previously examined in the National Research Council (NRC)
report Review of Secondary Waste Planning for the Blue Grass and Pueblo Chemical
Agent Destruction Pilot Plants (2008a). Instead, the following sections are intended to
provide a perspective on where additional monitoring tools might be useful. The ACWA
35
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36 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
pilot plants are full-scale facilities that face all of the normal state permitting
requirements that any industrial facility must comply with in terms of dealing with
effluents and waste streams. Since these general requirements are reasonably standard,
this report focuses on the unique aspects of monitoring for chemical agent contamination.
WASTE GENERATION AND MONITORING OVERVIEW
The various waste streams generated at BGCAPP and PCAPP can be classified as
primary or secondary:
Primary waste streams. Those encountered in conducting primary operations
for disposal (e.g., explosives removed and agent drained from munitions) that
are treated on-site, and
Secondary waste streams. Those generated by activities either in support of or
downstream of the primary processes for agent and energetics
destructionfor example, activated carbon, used demilitarization protective
ensemble (DPE) suits, dunnage, and so on that ultimately leave the facility.
These wastes include additional materials produced during facility closure
such as demolished concrete.
The characterization of the expected secondary wastes from the Pueblo and Blue
Grass facilities and the planning for their disposal were described in detail in NRC,
2008a. The purpose of that study was to "provide PMACWA with a technical appraisal
of its evolving plans to safely and efficiently handle, treat, and ultimately dispose of the
waste materials that remain following the destruction of the assembled chemical weapons
stored at PCD and BGAD" (p. 7). In the course of preparing the present report, the
ACWA Monitoring Committee received additional information on this subject.1
A general overview of the waste monitoring plan for PCAPP is shown in Figure
3-1, which itemizes the planned processes and corresponding analytical monitoring and
sampling methods. A corresponding diagram for BGCAPP was unavailable to the
committee, but the committee believes the PCAPP plan is reasonably illustrative and
representative for the purpose of this report. The analytical methods are categorized by
the primary process from which they originate and further identified by the type of
sample and key measurement parameter.
In the case of generator knowledge, sampling is not needed if there was no
opportunity for agent contamination to have occurred based on the Army's criteria shown
in Box 2-1. In other cases, headspace samples are taken after the waste is bagged or
tented and allowed to equilibrate. The sample is then taken from the vapor space above
the waste within the tented area, as described in the next section. In most cases, the
methods are derived from standard EPA methods; however, some methods were
1
This includes a presentation to the committee by Gary Groenewold, a member of the Committee
to Review Secondary Waste Disposal and Regulatory Requirements for the Assembled Chemical Weapons
Alternatives Program, "Sources and Amounts of Agent-Contaminated Wastes," on February 23, 2011, and
information provided by ACWA staff in response to committee questions or communications during site
visits.
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AGENT MONITORING PRACTICES FOR WASTE 37
developed specifically for the chemical agent destruction program. These methods are
indicated by the inclusion of the PCAPP method number (e.g., PCAPP-204).
The secondary waste streams anticipated during normal operations for PCAPP,
which only has munitions containing mustard agent, are summarized in Table 3-1. Table
3-2 shows the anticipated secondary waste expected from closure of PCAPP. The
corresponding secondary wastes expected from BGCAPP are presented in Tables 3-3, 3-
4, and 3-5. The waste streams are divided into "agent contaminated" (>1 VSL) and
"clean" (<1 VSL) based on the airborne exposure limits (AELs) and vapor screening
levels (VSLs) detailed in Tables 2-1 and 2-2. The distinction between "agent-
contaminated" and "clean" is important because it determines the type of handling
required and the type of waste treatment, storage, and disposal facility (TSDF) to which
the material can be sent.
At the time this report was prepared, PCAPP was further along on construction
than BGCAPP and had an approved waste analysis plan (WAP) in place.2 A draft WAP
submitted by BGCAPP as part of its Resource Conservation and Recovery Act (RCRA)
permit application for BGCAPP had not been approved at the time of this writing. From a
monitoring perspective, the only major difference between the two WAPs anticipated by
the committee is that at BGCAPP, a sequence of agents needs to be monitored as the
different agents are processed. The guiding principle for handling waste that may be
agent-contaminated was summarized on page 34 in NRC, 2008a:
Under the WAP filed with the Colorado Department of Public Health
and Environment (CDHPE), PCAPP will use generator knowledge as the primary
means of characterization, with direct sampling and analysis used to verify
process knowledge. Agent monitoring is conducted in accordance with the
Army's AEL guidance dated June 18, 2004). There are three approaches for
classifying and disposing of secondary waste relative to its contamination by
agent:
1. The waste is containerized and its headspace is monitored to determine the
appropriate classification: or
2. The waste is assumed to be agent-contaminated and is decontaminated in
accordance with the RCRA permit or regulations; adequate
decontamination (<1.0 VSL) is verified via monitoring at the SDU
[supplemental decontamination unit] or autoclave, whereupon it is
reclassified as "clean and shipped offsite; or
3. The waste is assumed to be agent-contaminated and is shipped offsite to a
facility permitted to receive such wastes.
For the purposes of this report, the committee again notes that the Army's
currently accepted means of characterizing agent-contaminated waste are generator
knowledge or the AELs established by the Army as described in Chapter 2. The AELs are
the basis for (1) quantifying the agent contamination measurements known as VSLs for
wastes subjected to controlled air monitoring and for (2) the established waste control
limits (WCLs) for wastes that must be analyzed by extractive procedures.
2
For example, see http://www.cdhpe.state.co.us/hm/pcd/adminrecord.htm, accessed on September
12, 2011.
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38 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
TABLE 3-1 Projected Amounts of Mustard-Agent-Contaminated Secondary
Waste from Normal Operations at PCAPP
Amount (lb)
Stream Description 1 VSL
Wood 0 56,906
Fiber tubes, additional packing material, metal strapping, 0 0
miscellaneous metal
TAP gear 9,639 6,709
Steel 0 0
Lead alloy 0 0
Aluminum 18 53
Brine reduction 0 0
Water recovery thickener residue 0 0
Energetics 0 0
Brass and copper wire 0 0
Charcoal from PPE mask containers 0 2,583
Inert bulk solid waste 15,421 35,790
Halogenated waste 3,153 2,661
DPE suits 121,514 81,010
Waste oils and spent hydraulic fluid 2,416 400
Leather 437 197
Absorbents 1,534 3,554
Paper/fiberglass/rubber 0 0
Polystyrene and polyethylene 669 2,318
Combustible solid waste 2,827 2,382
Waste paint sludge 915 455
Dry cell batteries 1,828 203
Lead acid batteries 1,219 135
Mercury-containing lighting 259 29
Total 161,849 195,385
SOURCE: PCAPP answers to Question Set 5 posed by the ACWA Secondary Waste Committee,
March 11, 2008.
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AGENT MONITORING PRACTICES FOR WASTE 39
TABLE 3-2 Projected Amounts of Mustard-Agent-Contaminated Secondary
Waste from Closure at PCAPP
Amount (lb)
Stream Description 1 VSL
Wood 0 0
TAP gear 3,704 412
Steel 0 0
Aluminum 21 7
Brine reduction 0 0
Water recovery thickener residue 0 0
Propellant 0 0
Brass and copper wire 0 0
Charcoal 0 1,000
Inert bulk solid waste 262,351 259,498
Halogenated waste 27,946 25,910
DPE suits closure 47,050 31,366
Waste oils and spent hydraulic fluid 927 164
Leather 147 98
Absorbents 350 3,153
Paper/fiberglass/rubber 0 0
Polystyrene and polyethylene (poly drums and 5-mil poly bags) 0 785
HEPA/prefilters 9,500 28,500
HVAC
30,690 3,410
Filtration charcoal
Filter plenums 15,300 1,700
Filter ductwork 9,000 1,000
Concrete 38,775 12,925
Combustible solid waste 26,359 26,503
Waste paint sludges and other sludges 0 531
Dry cell batteries 707 79
Lead acid batteries 472 52
Mercury-containing lighting 100 11
Total 473,399 397,102
SOURCE: PCAPP answers to Question Set 5 posed by the ACWA Secondary Waste Committee,
March 11, 2008.
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40 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
TABLE 3-3 Projected Secondary Waste Streams for >1 VSL Agent-
Contaminated Waste During Operations and Closure at BGCAPP
Projected Totals (lb)a
>1 VSL Waste Operationsb Closurec
Combustible solids 5,242 30,879
Metal 24,737 449,457
TAP gear/rubber 555 390
Halogenated plastic 9,957 73,505
Nonhalogenated plastic 2,209 18,786
Pre-HEPA filters 1,044 13,140
Agent collection system/spent 1,082 759
decontamination solution sludge
Concrete 0 50,053
Foam wall panel 0 31,371
Special coatings 0 4,052
Aluminum 0 2,149
Overpack waste 31,200 0
Total 76,068 674,540
NOTE: TAP, toxic agent protective; HEPA, high-efficiency particulate air; ACS,
agent collection system; and SDS, spent decontamination solution.
a
Totals calculated from estimated rate (lb/yr) data.
b
BGCAPP operations are estimated to have a duration of 2.08 years.
c
BGCAPP closure is estimated to have a duration of 1.46 years.
SOURCE: Adapted from PMACWA, 2006.
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AGENT MONITORING PRACTICES FOR WASTE 41
TABLE 3-4 Projected Secondary Waste Streams for <1 VSL Agent-
Contaminated Waste During Operations and Closure at BGCAPP
Projected Totals (lb)a
<1 VSL Waste (Unless
Otherwise Noted) Operationsb Closurec
Combustible solids 2,623 22,014
Metal 22,087 571,717
TAP gear/rubber 1,066 1,066
Halogenated plastic 14,360 151,039
Nonhalogenated plastic 1,733 20,994
3X pre-HEPA filters 82 5,084
Sludge 64 64
3X concrete 0 79,993
3X foam wall panel 0 50,136
Special coatings 0 6,475
3X aluminum 48 3,435
Total 42,063 912,017
NOTE: 3X refers to a formerly used decontamination level that indicates that the item has been
surface decontaminated by locally approved procedures, has been bagged or contained in an agent-
tight container of sufficient volume to permit an air sample to be withdrawn while minimizing
dilution with incoming air, and/or appropriate tests/monitoring have verified that concentrations
are not above 0.0001 mg/m3 for agent GB, 0.00001 mg/m3 for agent VX, or 0.003 mg/m3 for H.
Monitoring is not required for completely decontaminated and disassembled parts that are shaped
simply (no crevices, threads, or the like) and are made of essentially impervious materials (such as
simple lab glassware and steel gears) (NRC, 2007).
a
Totals calculated from estimated rate (lb/yr) data
b
BGCAPP operations are estimated to have a duration of 2.08 years.
c
BGCAPP closure is estimated to have a duration of 1.46 years.
SOURCE: Adapted from PMACWA, 2006.
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42 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
TABLE 3-5 Estimated Agent-Contaminated Waste Stream
Summary for Operations and Closure at BGCAPP
Total
Weight of
the Waste
Waste Designation (lb)
Inert bulk solid waste
Metal 1,243,545
Concrete 152,369
Aluminum waste 6,685
Foam core panels 95,498
Special coatings 12,333
Combustible bulk solid
Nonhalogenated plastics 50,972
Tap gear 4,555
HEPA filters and prefilters 19,997
Adsorbents, cottons, rags, bulk 4,477
Paper, wood, fiberglass, rubber 63,794
Halogenated plastics 308,404
Sludge 1,997
RCRA toxic metal-bearing waste
Paint chips 121
Leather gloves 224
Other 1,000
Waste oil and hydraulic fluids 1,620
Agent-contaminated activated carbon 103,488
Leaker campaign/overpack waste 15,000
Total 2,071,079
SOURCE: Adapted from BPBGT, 2006.
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AGENT MONITORING PRACTICES FOR WASTE 43
MONITORING BASED ON VAPOR MEASUREMENTS
Air Monitoring Instrumentation and Methods
The predominant time-honored methods for agent monitoring of both plant areas
and wastes depend on measuring airborne concentrations. The instrumentation and
methods used were most recently examined in the NRC report Monitoring at Chemical
Weapons Disposal Facilities (2005a). Other NRC reports over the last two decades have
also discussed monitoring instrumentation and methods in the context of those reports'
subject matter.3 The focus on disposal site monitoring and measuring airborne agent has
been appropriate because vapor constitutes the most probable means of exposure for
workers and is the only pathway by which the public could be exposed.
Miniature continuous air monitoring systems (MINICAMS) are the workhorse
units chosen for airborne monitoring at PCAPP and BGCAPP; they provide near-real-
time (NRT) data (5-15 min). Backup monitoring for confirmatory and historical purposes
is provided by the depot area air monitoring system (DAAMS) collection tubes that
adsorb and preconcentrate agent vapors from ambient air over a period of time. These
collection tubes are transported to an on-site laboratory and their contents are regularly
(daily or longer) flash-desorbed analyzed by gas chromatography/mass spectrometry
(GC/MS). Results from the DAAMS tubes have a turnaround time of up to 72 hours and
are thus not in real time or near real time, but do have the strength of providing a
cumulative and historical record of agent vapor presence, even at very low
concentrations.
In addition to their role in monitoring areas where agent contamination is
expected, MINICAMS are also installed near to the areas where personnel might be
exposed to agent. MINICAMS also are used for detection of leakers in storage igloos; in
containers used to transport munitions from the igloos to the munitions storage magazine
(MSM); and in transport vehicles from the MSM to the enhanced reconfiguration
building. PCAPP anticipates that 132 MINICAMS will be required to support its
operations.4
MINICAMS are also used for headspace monitoring of waste materials prior to
shipment to an off-site TSDF, as mentioned above. The measurement cannot exceed the
established WCLs, which are defined in terms of a VSL for each agent. As noted above,
headspace monitoring of the waste involves placing it in an enclosure at a prescribed
temperature for a sufficient amount of time to allow agent present on the solid to
equilibrate with agent in the vapor. If the vapor-phase concentration is <1 VSL, the waste
is deemed to be clean. Target release levels are generally somewhat lower than the WCLs
to allow a margin for error and still be in compliance with the WCL values approved by
state regulatory authorities.
One possible use of direct surface analysis using ambient ionization mass
spectrometric technology could be to help resolve those instances where prior exposure
3
Examples include NRC, 1994; 2002; 2005d; 2010.
4
PCAPP Air Monitoring Strategies and Secondary Waste, discussion between Walter Waybright,
PCAPP Laboratory Manager, and the committee, on June 28, 2011.
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44 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
of materials to agent is in question. However, it should be noted that neither headspace
concentrations (VSLs) nor concentrations determined from alternative extractive solvent
analyses (discussed below) are directly and quantitatively derivable from surface
concentrations. A first-order surface concentration measurement might entail obtaining a
qualitative answer as to whether or not to analyze further. A conservative estimate of a
corresponding gas-phase concentration could be made by assuming 100 percent
desorption of the measured surface agent concentration multiplied by an estimated
contaminated surface area to specify a total adsorbed agent mass, and then applying the
ideal gas law to compute the potential gas phase agent concentration (mass per unit
volume) in the headspace volume.
The immediate opportunities for ambient ionization monitoring techniques lie
either in improving internal operation of the plant or in identifying materials with
strongly absorbed agent that must be managed accordingly. By improving internal
operations, the committee is referring to possible enhancements to worker safety and to
potentially enabling the time needed for overall disposal and closure operations to be
shortened.
Extractive Analysis
Hazard analyses for work procedures conducted at chemical agent disposal
facilities attempt to scrupulously avoid possibilities for dermal contact with chemical
agent by workers. The use of appropriate-level personal protective equipment is among
the prescribed means by which dermal contacts with agent are avoided. Consequently, the
vapor-phase monitoring methods described above are aimed at controlling and providing
valid measurements of the inhalation threat to workers posed by ambient airborne agent
concentrations.
Meanwhile, certain waste materials (e.g., carbon and wood) are not amenable to
accurately measuring the extent of agent contamination from headspace vapor monitoring
owing to their physical properties (e.g., adsorptivity and absorptivity). The 2009 NRC
report Disposal of Activated Carbon from Chemical Agent Disposal Facilities described
the problem in using headspace vapor analysis for one such major waste stream
(activated carbon) as follows (NRC, 2009b, p. 42):
. . . to use this method to accurately measure agent loading on carbon requires
measurement of the gas-phase concentration in equilibrium with the carbon and
also requires knowledge of the adsorption isotherm for that agent under relevant
conditions. In principle, if the adsorption isotherm is known, then the adsorbed-
phase concentration or loading can be determined from the gas-phase
concentration. Three issues associated with the use of headspace analysis must be
considered to achieve a reliable analysis of agent loading on carbon. First, the
gas-phase concentration of agent that would be in equilibrium with an agent
loading of 20 ppb at ambient and even moderately elevated temperatures could
be undetectable by head space analysis. Second, the adsorption isotherm would
be needed to correlate loadings with gas-phase concentrations at agent loadings
near 20 ppb. Third, a pure-component adsorption isotherm would not even apply
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AGENT MONITORING PRACTICES FOR WASTE 45
to the real system, which would contain co-adsorbed amounts of other
components, such as water and degradation products.
Given the issues and problems surrounding accurate determinations of the degree
of agent contamination for materials such as activated carbon using vapor-phase methods,
the Army and various regulatory authorities have instead turned to requiring
characterization of agent concentrations by analytical extraction procedures. These are
described in EPA publication SW-846, Test Methods for Evaluating Solid Waste,
Physical/Chemical Methodsspecifically, Method 3571, "Extraction of Solid and
Aqueous Samples for Chemical Agents," and Method 8271, "Assay of Chemical Agents
in Solid and Aqueous Samples by Gas Chromatograph/Mass Spectrometry, Electron
Impact (GC/MS/EI)" (EPA, 2007a,b).5
Several of the process monitoring methods summarized in Figure 3-1 involve
extraction of a liquid sample aliquot containing potentially contaminated solid material,
which would be subsequently analyzed in the laboratory by the techniques described in
Methods 3571 and 8271 While they provide an alternative means to more accurately
measure agent contamination, these methods involve time-consuming and difficult
operations. That is, any method that requires taking an aliquot to a laboratory for analysis
is far from real time, and it would seem desirable if it could be replaced with a real-time
method. The new ambient ionization mass spectrometric methods offer the possibility of
real-time agent contamination measurements of porous materials for the first time, giving
the Army's chemical demilitarization community the opportunity to consider their utility.
In addition, as shown in subsequent chapters, ambient ionization mass spectrometry
methods are capable of quantifying low levels of relevant agents in liquid solutions.
Thus, it may be feasible to analyze liquid extraction samples where they are collected
without transport for laboratory analysis. For the purposes of this report, the committee's
examination will focus on the most immediate and largest needs to characterize porous
materials, activated carbon and concrete, which will be discussed in more detail in later
sections of this chapter and in subsequent chapters.
USE OF DPE SUITS DURING PLANT OPERATIONS
The largest single secondary waste category generated during normal operations
at PCAPP (Table 3-1) is expected to be nonporous DPE suits: over 200,000 lb, of which
81,000 lb are anticipated to be >1 VSL. This represents roughly 40 percent of all
anticipated waste with >1 VSL. Much of the DPE waste originates from routine
maintenance entries into Category A areas, where agent is expected to be encountered.
Another 78,000 lb or so of DPE waste are anticipated to be generated during closure
operations at PCAPP. Unfortunately, DPE suits are not specifically itemized in Tables 3-
3, 3-4, and 3-5 from BGCAPP, but the committee presumes that DPE suits, constructed
5
SW-846 is the EPA Office of Solid Waste's (OSW's) official compendium of analytical and
sampling methods that have been evaluated and approved for use in complying with the RCRA regulations.
SW-846 functions primarily as a guidance document setting forth acceptable methods for the regulated and
regulatory communities to use in responding to RCRA-related sampling and analysis requirements.
Additional information is available at www.epa.gov/osw/hazard/testmethods/sw846/.
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48 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
FIGURE 3-2 Workers in personal protective equipment working at a chemical weapons disposal facility.
SOURCE: CMA Fact Sheet on Safe Disposal of Secondary Waste. Available online at www.cma.army.mil.
touch the outside of the suit where agent might still be present. The assistant
comes in solely to help the workers doff their suits, not to help decontaminate.
The aim is to help a worker avoid contact with the outer surface of the suit,
where contamination may be present.
Hot cutout. This type of egress occurs when there is a high level of residual
contamination that cannot be successfully decontaminated. (For example, the
agent might be embedded in grease on the suit.) An assistant wearing a higher
level of PPE gear, such as a self-contained breathing apparatus along with
gloves, boots, and other dermal protection, would enter the airlock to help
remove the worker's suit.
Emergency cutout. In an emergency cutout there is some medical urgency
(e.g., heat stress) such that there is no time to decontaminate and verify. The
cutting out in this fast-moving situation is done in an expedited way by a
backup rescue team, which may consist of one worker in Level B PPE and
another in Level C, or both workers in Level B. This team does not look for
contamination; rather, they will do a gross decontamination with the emphasis
on avoiding contact with the outside surface of the suit. When the call is made
for the rescue team, the other DPE-suited worker will immediately hose down
or start dropping buckets of decontamination solution on the DPE-casualty
worker while in the work area to provide some benefit before the rescue team
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AGENT MONITORING PRACTICES FOR WASTE 49
gets there to extract the stricken worker. Typically, one member of the rescue
team will enter the area and work with the other DPE-suited worker to extract
the DPE-casualty worker while the other member of the rescue team prepares
to receive the stricken worker. For example, one litter or sled might go into
the work area with one of the rescue team members while the other member
prepares another litter or sled to which the casualty worker will be transferred
for handoff to a medical team. In an emergency egress (medical, fire, etc.) the
DPE-suited workers will not necessarily leave through an airlock but may use
an alternative emergency exit door.
Clearly, these classifications become more problematic going down the list from
the normal cutout to the emergency cutout. Each of the egress categories could be
expedited by having a quick-response, real-time monitoring device capable of
pinpointing areas of agent contamination and/or by verifying the lack of agent. Such a
capability would help ensure the safety of workers. Scenario 3A in Box 3-1 describes
how the new monitoring techniques might be of value.
BOX 3-1
Scenario 3A: Improving Worker Safety During DPE Entries
Worker safety is of paramount concern, and knowing as rapidly as possible where
agent is or is not would facilitate smarter and safer DPE activities.
Faster quadrant scanning would speed normal DPE cutout time, and more
accurate pinpointing of any residual agent on the DPE suit could guide workers to focus
further decontamination on those spots. If further decontamination is not possible, the
information could be used to avoid contaminated spots. Also, real-time monitoring of
materials left in the wake of an extracted worker might help coworkers avoid
contamination.
The use of portable ambient ionization instrumentation might allow faster
assessment of agent presence for DPE activities and expedite safer worker egress.
DPE suits that have been exposed in Category A areas are assumed to be
contaminated and require monitoring for agent contamination. That is typically
accomplished by headspace analysis, as described in the ACWA Chemical Agent
Monitoring Concept Plan (MCP) for personal protective clothing and equipment (PCE)
(U.S. Army, 2011a, p. 59):
To monitor decontaminated PCE, the PCE will be placed in a container or room
and held for at least 4 hours at a minimum temperature of 21o C (70o F) . The
atmosphere (i.e., headspace) inside the container or room will be monitored for
contamination via a technique applicable to the monitoring level of interest (VSL
or 8-hour WPL) to verify that agent concentrations are below the applicable AEL
before the PCE may be sent to the laundry facility. If agent concentrations are
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50 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
BOX 3-2
Scenario 3B: Enabling More Efficient DPE Entries
DPE entries into contaminated process areas place great physical strains on
workers in DPE gear and also involve potential agent exposures. In addition, munitions
processing must usually be suspended during entry operations. Opportunities to focus and
expedite entry activities may lead to safer entries and shorter process interruptions and
the generation of less DPE secondary waste.
Portable ambient ionization instrumentation may allow quick and reliable
determination of agent contamination locations and levels during DPE entriesfor
example, by determining if observed liquid deposits are agent or nonagent (water, oil), by
clearly defining contaminated areas to focus decontamination actions and confirm their
effectiveness, and by generally expediting effective decontamination activities that in
turn would allow workers to downgrade the level of personal protection necessary to
work in contaminated areas when appropriate.
detected above the applicable AELs, the PCE will be further decontaminated and
remonitored.
PCE includes DPE suits. While headspace analysis is a proven and effective method for
verifying whether DPE suits are clean, it is also time consuming.
Scenario 3B in Box 3-2 provides a scenario for possibly reducing the number of
DPE suits used during process maintenance, agent changeover, and closure activities.
Finding 3-2. Any new monitoring method that could efficiently and reliably locate and
quantify agent contamination may make decontamination activities more efficient by:
Enabling faster identification of leaking munitions and decontamination of
machinery, potentially reducing the number and/or duration of DPE-suited
entries during normal plant operations, agent changeover periods, and closure
activities;
Reducing the total amount of secondary waste;
Speeding waste disposal; and
Minimizing worker exposure.
CHANGEOVER OF AGENT DISPOSAL CAMPAIGNS AT BGCAPP
At BGCAPP, chemical agents will be destroyed in sequential campaigns
beginning with GB, which due to its relative volatility presents the greatest risk, and then
proceeding to VX. A decision is pending on whether all or only some of the mustard
agent H projectiles should be destroyed by use of an explosive destruction technology
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AGENT MONITORING PRACTICES FOR WASTE 51
(EDT) instead of being processed through the main BGCAPP processes. During the
changeover period from one agent to the next, the MINICAMS are reconfigured to
monitor for the next agent to be destroyed. The facility and associated equipment and
machinery must be completely decontaminated of the prior agent before operations can
continue.
In preparation for changeover, occluded space teams (OSTs) are formed to
identify occluded spaces that may harbor agent contamination. Common areas of
occluded space include closed pipes, pump cavities, cracks in concrete, and caulking
seals around equipment or concrete joints. Discussions and definitions of the types of
occluded spaces that may occur in chemical weapons disposal facilities are presented in
Box 3-3. Where possible, equipment having occluded spaces will be bagged for
headspace analysis to verify contamination levels.7
If headspace analysis indicates contamination of a large piece of equipment, it
might prove beneficial to have a more local, real-time probe (such as ambient ionization
mass spectrometry for surface analysis) that could pinpoint the contaminated area for
decontamination. Changeover operations typically take several months to complete and
any reduction in the period of time necessary for changeovers would speed the overall
disposal campaign. The committee believes it could be beneficial to identify situations in
which bagging could safely be eliminated, or at least greatly reduced, by use of surface
analysis by ambient ionization mass spectrometry. In this method, a wand would be
waved over the surface of, for example, a contaminated machine or a cavity identified by
an OST that would otherwise require bagging and headspace monitoring. Examples of
how a real-time surface analysis instrument could speed changeover are given in Scenario
3C in Box 3-4 and Scenario 3D in Box 3-5.
Finding 3-3. A local, real-time agent monitoring system capable of monitoring surfaces
might enhance the effectiveness of occluded space survey teams by identifying
problematic occluded spaces and identifying other sources of contamination, possibly
reducing the time necessary to conduct agent changeovers or facility closure.
CLOSURE OPERATIONS
Once a chemical agent disposal facility has completed the disposal campaign
operations for all agents stored at the site, it transitions into closure operations. This
involves the decontamination and removal of equipment and decontamination and
demolition of any contaminated infrastructure and buildings areas. The objective of
closure is to decontaminate and safely demolish to ground level, in a manner that
provides for the safety and protection of the workers, the public, and the environment, all
of the buildings that were exposed to agent contamination (NRC, 2010). Such closure
activities must satisfy regulatory permit requirements and other applicable federal, state,
and local stipulations whether or not the area is destined to be returned to the public
7
Gary Groenewold, member of the Committee to Review Secondary Waste Disposal and
Regulatory Requirements for the Assembled Chemical Weapons Alternatives Program, "Sources and
Amounts of Agent-Contaminated Wastes," presentation to the committee on February 23, 2011.
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52 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
BOX 3-3
Definition and Classification of Occluded Spaces
The term "occluded space" is generally interpreted by the U.S. Army CMA as "a confined
volume within a system, structure, or component that was exposed or potentially exposed to liquid
agent and has the potential to contain any quantity of agent contaminated liquid."1 Building on this
definition, it is useful to classify occluded spaces into three broad types. Note that the following types
do not reflect an official classification protocol by the U.S. Army but are presented for descriptive
purposes in this report.
Occluded space, Type I. This category of occluded space is putatively the largest of the three
categories. It represents areas that agent in liquid or vapor form could potentially penetrate and/or
reside in that would hinder or preclude its detection by vapor screening methods (e.g., tenting). To
avoid erroneous vapor screening measurements, systems, structures, and/or components are
disassembled prior to VSL measurements to eliminate Type I occluded spaces before demonstrating
that decontamination was successful. The derivative pieces following disassembly, for example, steel
parts and laboratory glass, typically exhibit readily defined surfaces with smooth geometries.2
Examples of Type I occluded space include seams, crevices, cracks, fasteners, threads, tubing, valves,
and unsealed joints.
Occluded space, Type II. This category of occluded space represents process system or structural
components containing materials with properties of porosity, miscibility, and/or chemical affinity for
the liquid agent. In these cases, there is a reasonable probability that any exposure to high levels of
gaseous agent, liquid agent, or agent contaminated liquids may have resulted in significant quantities
of agent being adsorbed, absorbed, and/or trapped within the matrix of the material. This may result in
misleadingly low values of agent vapor concentration when VSL measurements are performed.
Typically, such materials are either incinerated (at CMA demilitarization facilities equipped with
suitable furnaces) or stored prior to chemical neutralization on-site. Examples of Type II occluded
spaces include wooden pallets, spent activated carbon, polymer gaskets, pump oil, lubricating oil,
porous materials (including spill pillows), and agent miscible liquids.
Occluded space, Type III. The third category of occluded space is challenging to anticipate, foresee,
and detect, as it represents potential occluded spaces in the process system or structural components
that may have been present upon initial fabrication or construction or that became occluded at a later
time, either in use during agent destruction campaigns, or even following decommissioning and
shipment of the material off-site. These occluded spaces may arise from nonideal construction of the
individual process system or structural components that remain undetected or are thought to be
impervious, or they may not exist during plant systemization but arise laterfor example, through
material degradation by geological, environmental, or chemical forces. Although it is difficult to
assess the extent of Type III occluded spaces (if any), it is nevertheless important to recognize their
potential to occur and become exposedfor example, during decommissioning or deconstruction
campaigns and, longer term, as sequestered wastes age, such as those decontaminated to level 3X or
5X (NRC, 2007), that are shipped off-site for long-term disposal (e.g., in landfills).
____________________________
1
J.M. Kiley, 2011. "Closure Briefing," presented to the committee on February 23, 2011.
2
NRC. 2007. Review of Chemical Agent Secondary Waste Disposal and Regulatory
Requirements, Box 3-1 "U.S. Army Decontamination Metrics for Potentially Exposed Materials,"
p. 40.
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AGENT MONITORING PRACTICES FOR WASTE 53
BOX 3-4
Scenario 3C: Process Area Occluded Space Surveys and/or Absorbed Agent
Surveys During Changeover or Closure Activities
Unventilated agent vapor monitoring shows that a process area is contaminated. A
portable ambient ionization instrument might be able to quickly interrogate and survey
identified occluded spaces or suspected absorbed agent-contaminated materials,
machinery, equipment, and plant structures, including concrete walls, floors, seams, and
interfaces, to determine if agent reservoirs might be present and, if they are, guide and
confirm focused decontamination efforts, thus reducing changeover or closure time.
BOX 3-5
Scenario 3D: Complex Contaminated Demilitarization Machine Needs
Decontamination at Agent Changeover or Closure Activities
Bagging and monitoring headspace levels is not practical for some equipment,
materials, and machinery and may not be the most cost-effective approach for others. A
portable ambient ionization instrument might be able to quickly survey occluded spaces
and/or absorptive material components and identify the contaminated parts to direct
focused decontamination or component removal to expedite treatment.
domain. These operations produce large amounts of secondary waste, as summarized in
Tables 3-2 through 3-4. To minimize decontamination and to protect workers, a well-
defined process is followed based on established AELs for the agents (see Table 2-1).
This process includes the following:
Maintaining and reviewing documented agent history. Based on lessons
learned at prior closure operations, a careful record of all contamination
events, spills, leaks, and the like is maintained during plant operation and used
to identify contaminated areas by what is termed "generator knowledge."
Selecting decontamination methods for each type of waste.
Using OSTs to survey the facility and identify occluded spaces where agent
may have accumulated. These include hidden spaces in piping, pumps, etc.,
that are not readily cleaned and decontaminated.
Decontamination, monitoring, and dismantlement of equipment. Figure 3-3
shows tenting of a large piece of equipment in preparation for vapor
monitoring.
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54 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
FIGURE 3-3 An example of a large item tented for monitoring at closure. SOURCE: Jeff Kiley, Chief,
Quality Assurance, CMA, "CWD Closure Briefing," presentation to the committee on February 23, 2011.
Decontamination and unventilated monitoring of the enclosed air space of
building areas and rooms subject to having been contaminated by agent.
Finally, razing buildings to the ground level.
Uncontaminated buildings may be retained based on agreement with the
respective depot (Pueblo Chemical Depot or Blue Grass Army Depot) and any plans
under base realignment and closure (BRAC) agreements. The criteria used to determine if
an area is contaminated are contained in a U.S. Army review (2008a) and specified in the
local environmental permits. Generally, the criteria areas are as follows:
Any area or chamber exposed to liquid agent or aerosol is assumed to be
contaminated.
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AGENT MONITORING PRACTICES FOR WASTE 55
Any area or chamber exposed to agent vapor above the immediately
dangerous to life or health (IDLH) level is considered to be contaminated.
A decision on whether an area that has been exposed to agent vapor between
IDLH and the short-term exposure limit (STEL) is contaminated is based on a
risk assessment.
Any area or chamber that has only been exposed to agent vapor below the
STEL is assumed to not be contaminated.
Table 3-2 summarizes secondary wastes expected from closure operations at
PCAPP and Tables 3-2 and 3-4 provide similar expectations for BGCAPP. Although the
two sites use different terminology to describe some of their waste, much of the waste
from normal operations, including from DPE suits and other toxicological agent
protective (TAP) gear, continue to be major contributors during closure. In addition,
closure creates significant streams of concrete, metals, combustible solids, and other
incombustible solids. Also, all the activated carbon from the heating, ventilation, and air
conditioning (HVAC) filter system must be disposed of at closure.
Special challenges to agent contamination monitoring are presented by some of
these materials. For example, activated carbon is a strong absorber of agent, and concrete
can be porous and can have cracks that accumulate agent. Combustible wood and fabric
materials are often fibrous or porous, and agent may strongly adhere or absorb. Porosity
can effectively provide large volumes of occluded space that are highly agent-retentive.
As a lesson learned from prior chemical demilitarization sites, concrete that could
potentially become exposed to liquid agent is of a high density and coated with a special
polymer intended to minimize agent access to any cracks or pores. At BGCAPP and
PCAPP, it is anticipated that this will minimize the need for scrabbling to remove agent-
contaminated layers of concrete.
The current method of monitoring for agent adsorbed on or absorbed in concrete
is headspace monitoring of nonventilated tented walls; this procedure includes heating to
aid in vaporizing absorbed agent.8 A previous NRC report questioned whether scrabbling
would cause even more concrete to be classified as agent contaminated and
recommended that ACWA investigate means for measuring residual agent on the
concrete surfaces (NRC, 2008a, Recommendation 4-4). This committee concurs with that
recommendation and suggests that ambient ionization mass spectrometry be investigated
for that purpose. It now offers Scenario 3E (Box 3-6) as a possibility for further
discussion in Chapters 4 and 5.
Finding 3-4. Materials with inherent porosity can readily adsorb or absorb agent and
present a monitoring challenge for headspace vapor measurement methods.
8
Personal communication from James Richmond, Director, ACWA Risk Management Directorate,
to the committee, August 15, 2011.
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56 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
BOX 3-6
Scenario 3E: Concrete Waste Contamination Evaluation
Concrete that will have to be disposed of at closure may have agent adsorbed to
its surfaces or absorbed into its mass. A portable ambient ionization instrument might be
able to quickly and reliably interrogate adsorbed agent on the concrete surfaces and/or
absorbed agent in bulk concrete to identify contaminated areas, estimate contamination
levels, and reduce the need for scrabbling.
ACTIVATED CARBON DISPOSAL
Activated carbon (also referred to as charcoal in Tables 3-1 and 3-2) strongly
absorbs agent and other organics and is thus used in protective masks for workers and the
final filter banks before air is released from the plant. The bulk of the activated carbon
must be disposed of at closure. Over 100,000 lb are expected to be disposed of at
BGCAPP (Table 3-5) and about 35,000 lb at PCAPP (Table 3-2).
Activated carbon is a porous adsorbent that cannot be verified to be free of agent
by headspace analysis because the agent is strongly adsorbed on or absorbed in the
carbon. Shipment of agent-exposed activated carbon to off-site disposal or recycling
facilities requires verifying the mass of agent on the carbon. The method currently being
pursued is solvent extraction of the adsorbed/absorbed phase from the carbon sample
followed by GC/MS analysis. Applying this method at the Anniston Chemical Agent
Disposal Facility (ANCDF) in Alabama, Southwest Research Institute found that VX was
below the WCL but GB was above it. The GB values were later ascribed to the re-
formation of GB from the hydrolysis products during extraction. A way was found to
limit this re-formation, but if a real-time analysis technique were available that would not
require extraction, it might prove to be a better alternative.
The NRC-recommended solution for the ultimate disposal of the activated carbon
at ANCDF was to fill the polyethylene drums that held the carbon with caustic solution
prior to transporting them to a treatment, storage, and disposal facility (TSDF) (NRC,
2009b). Scenario 3F in Box 3-7 asks whether surface ambient ionization mass
spectrometry might be able to directly measure agent contamination on carbon, which
might lead to more informed carbon disposal decisions.
BOX 3-7
Scenario 3F: Spent Activated Carbon Contamination Evaluation
Spent activated carbon is likely to have bulk absorbed agent. A portable ambient
ionization instrument might be able to quickly and reliably interrogate adsorbed/absorbed
agent in spent activated carbon to identify contaminated materials, estimate
contamination levels, and thus inform and focus decontamination or disposal activities.
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AGENT MONITORING PRACTICES FOR WASTE 57
SCENARIOS SUMMARY
From a technical specifications perspective, the successful implementation of any
new technologies to any of the scenarios presented in this chapter would represent a
considerable departure from current agent monitoring practice, most noticeably in the
detection of absorbed or chemisorbed materials on surfaces. In addition to directdetection
on surfaces, a number of other analytical properties are critical to successful
implementation for any particular application. These include purely analytical parameters
such as sensitivity, dynamic range and selectivity as well as instrument factors such as
reliability, portability, and ease of operation. Table 3-6 summarizes some of the criteria
important to meeting the requirements of the different scenarios presented in this chapter.
Chapters 4 and 5 will address the technical suitability of certain types of ambient
ionization mass spectrometry for surface-adsorbed agent analysis.
TABLE 3-6 Critical Measurement Performance Criteria for Possible Scenarios
Scenario Critical Performance Criteria Categories for Measurements
Detect on Surfaces
Short Duty Cycle
Reconfiguration
Dynamic Range
Precise Target
Rapid Result
Localization
Specificity
Sensitivity
Portability
Scanning
Rapid
3A Improving worker
X X X X X
safety during DPE entries
3B Enabling more efficient
X X X X X
DPE entries
3C Process area occluded
space surveys and/or
absorbed agent surveys X X X X X X X
during changeover or
closure activities
3D Complex contaminated
demilitarization machine
needs decontamination at X X X
agent changeover or closure
activities
3E Concrete waste
X X X X
contamination evaluation
3F Spent activated carbon
X X X
contamination evaluation
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