Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 11
2
BGCAPP and PCAPP Designs and Relevant Procedures Used at
Destruction Facilities
As described in Chapter 1, during the 2002-2003 time frame, the U.S. Department
of Defense Assistant Secretary of the Army for Acquisition, Logistics, & Technology
(AL&T) issued a number of directives adopting the use of neutralization (chemical
hydrolysis) as the primary means for destroying the chemical agent in assembled
chemical munitions stored at both the Pueblo Chemical Depot (PCD) in Colorado and the
Blue Grass Army Depot (BGAD) in Kentucky.
In brief, the neutralization process entails mixing the chemical agent mustard with
hot water or the nerve agents GB and VX with hot caustic solution.1 Under these
conditions, the chemical agents react with water, producing hydrolysate products that are
less toxic but still require further treatment. At two former sites that only had bulk agent
stored in 1-ton containers, neutralization had been used successfully and the Army was
able to send the hydrolysate off-site for final treatment. In contrast, at BGCAPP and
PCAPP, current plans call for on-site secondary treatment of hydrolysate before the final
products can be sent off-site for disposal.
The processes selected by the Army for secondary treatment of hydrolysate are
biotreatment at Pueblo and supercritical water oxidation at Blue Grass. These processes
are adapted and implemented by the site system contractors and are subject to validation
of their effectiveness, budgetary constraints and state regulations.
The disposal processes planned for use at PCAPP and BGCAPP and the waste
streams they will produce are described below. More detailed descriptions of the unit
operations can be found in prior NRC reports (NRC 2005b, 2005c) and on the ACWA
Web site.2
At the time this report was prepared, PCAPP had been issued a Resource
Conservation and Recovery Act (RCRA) Research Development and Demonstration
(RD&D) permit from the Colorado Department of Public Health and the Environment
(CDPHE). BGCAPP has also applied for a RCRA RD&D permit from the Kentucky
Department of Environmental Protection.3 In recognition of the significant degree to
which the alternative technology designs for the two sites include first-of-a-kind (FOAK)
1
Detailed information on the composition and the chemical and physical properties of the mustard
agents (HD, HT) and nerve agents (GB and VX) relevant to ACWA agent destruction activities is presented
in Chapter 4 (see Table 4-1 and Figure 4-8).
2
The ACWA Web site is at http://www.pmacwa.army.mil/.
3
Additional information concerning the PCAPP and BGCAPP permits can be found through the
site links at http://www.pmacwa.army.mil/.
11
OCR for page 12
12 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
equipment and process technologies that have not been previously implemented at full
scale, these facilities are designated as pilot plants, i.e., the Pueblo Chemical Agent
Destruction Pilot Plant (PCAPP) and the Blue Grass Chemical Agent Destruction Pilot
Plant (BGCAPP). However, each facility will have the capacity to destroy the entire
chemical weapons stockpile stored at its location. The designs for these facilities have
undergone a number of revisions from their original design proposals in 2004, and some
downsizing for both technical and budgetary reasons. However, the designs have now
been fixed and construction of the two plants is well under way. The RD&D permitting
process recognizes the need for flexibility, and negotiations with regulators are ongoing
at both sites. Table 2-1 lists the process equipment and machinery at both sites and their
potential for being contaminated by agent.
In this chapter, the committee provides background on the safety regulations,
procedures, and terminology that are used at chemical destruction facilities. The agent
process designs at PCAPP and BGCAPP are also briefly described, followed by a
description of the heating, ventilation, and air conditioning (HVAC) systems (the largest
source of potentially contaminated activated carbon) common to both plants.
BACKGROUND ON SAFETY PROCEDURES AND REQUIREMENTS USED AT
CHEMICAL AGENT DESTRUCTION FACILITIES
The safety procedures and activities related to agent contamination at chemical
demilitarization facilities are based on the airborne exposure limits (AELs) that were set
by the Centers for Disease Control and Prevention (CDC) in 2003 and 2004 and adopted
by the Army, as described in pamphlet DA PAM 385-61, Toxic Chemical Agent Safety
Standards (U.S. Army, 2008). The draft document entitled Assembled Chemical Weapons
Alternatives (USAE ACWA) Chemical Agent Monitoring Concept Plan, which describes
in detail the standards, processes, and procedures for protecting personnel and the public
at the two ACWA sites, is the primary reference for the discussion that follows (U.S.
Army, 2011a). Types of AELs based on vapor concentrations and duration of inhalation
exposure doses are defined and presented for the three relevant chemical agents in Table
2-2. Guidelines from Volume 3 of Acute Exposure Guideline Levels for Selected
Airborne Chemicals that were developed as acute exposure guideline levels (AEGLs) for
various chemical agents, specifically GB, VX, and mustard agent in this case, are also
included in Table 2-2 (NRC, 2003). Both sets of exposure levels are used by the Army.
As briefly mentioned in Chapter 1, the contamination level of waste is often
determined by sealing it in a bag or, for large equipment, a plastic "tent" enclosure at
70°F or warmer, for a time sufficient for agent vapor to equilibrate with the waste in the
ambient air space. Headspace agent vapor concentrations are then determined by a near-
real-time (NRT) agent monitor, such as a miniature continuous air monitoring system
(MINICAMS). The Army defines NRT as a measurement cycle of between 5 and 15
minutes. This is a system that provides monitoring for airborne chemical warfare agent
using an automated gas chromatograph. The vapor screening levels (VSLs) defined and
presented in Table 2-2 typically determine whether the waste can be shipped off-site
without further on-site treatment in accordance with site-specific RCRA permit
requirements. To be reutilized, an item must meet release levels given in Table 2-3.
OCR for page 13
BGCAPP AND PCAPP DESIGNS AND PROCEDURES 13
TABLE 2-1 Processes and Unit Operations Being Used at PCAPP and BGCAPP
FOAK
Equipment Site(s) Function Note
Rocket shear BGCAPP To separate rocket motors from the This unit will not be
machine (RSM) warhead, drain agent from the contaminated unless a leaking
warhead, and shear the warhead into munition contaminates it.
small pieces to be sent to the EBHs
Linear projectile BGCAPP To disassemble projectiles and This unit will not be
mortar PCAPP mortars and remove their bursters contaminated unless a leaking
disassembly munition contaminates it.
machine
(LMPD)
Munitions BGCAPP To remove the burster well from This unit and the room will be
washout station PCAPP projectiles, drain the chemical agent, contaminated.
(MWS) and wash out any agent residues
Energetic bulk BGCAPP To neutralize energetics and any This unit and the explosive
hydrolyser chemical agent in the metal parts of containment room will be
(EBH) the rockets and fuzes from projectiles contaminated.
Metal parts BGCAPP To decontaminate projectile bodies The front end of this unit will be
treater (MPT) and secondary waste by heating to in a contaminated atmosphere,
over 1000F for more than 15 min but the back end, where the
metal parts are removed, will
not be in a contaminated area.
Munitions PCAPP To decontaminate projectile bodies The front end of this unit will be
treatment unit and secondary waste by heating to in a contaminated atmosphere,
(MTU) over 1000F for more than 15 min but the back end, where the
metal parts are removed, will
not be in a contaminated area.
Supercritical BGCAPP To treat agent energetics This unit is outside the agent area
water oxidation hydrolysates before releasing them fence and will be in a non-
(SCWO) for final disposal contaminated area.
Immobilized cell PCAPP To treat mustard hydrolysate before This unit is outside the agent
bioreactors releasing it for final disposal area fence and will be in a non-
(ICBs) contaminated area.
SOURCE: NRC, 2011.
Vapor screening methods are also used to determine if potentially contaminated
workspaces require decontamination during agent changeover or closure activities. In
these cases, NRT agent vapor monitors are deployed in unventilated areas to determine if
agent vapor levels rise above 1 VSL. While these vapor screening procedures have been
used to safely characterize agent contamination of both solid waste materials and
structural components at CMA chemical demilitarization sites for the past two decades,
they are time consuming and do not directly identify the specific contaminated surface
areas that may require further decontamination.
OCR for page 14
TABLE 2-2 Airborne Exposure Limits, Vapor Screening Levels, and Acute Exposure Guideline Levels for Chemical Agents
Agent-Specific Quantities (mg/m3)
Exposure Limit Type Definition GB VX HD
Airborne Exposure Limit
General population limit (GPL) The concentration limit in which an unprotected general population can be exposed 24
hr/day forever without any adverse effects. Time-weighted average: HD, 12 hr; VX and 1 × 10-6 6 × 10-7 2 × 10-5
GB, 24 hr.
Worker population limit (WPL) The concentration at which an unprotected worker can operate safely 8 hr a day for 5
(8 hours) days per week for a working lifetime without adverse effects. Time-weighted average 3 × 10-5 1 × 10-6 4 × 10-4
all agents: 8 hours/workday and 40 hour/week for 30 years.
Short term exposure limit The level at which an unprotected worker can operate for a 15 min period. The
(STEL) frequency is once per day for HD and VX and four times per day for GB during an 8 hr 1 × 10-4 1 × 10-5 3 × 10-3
workday. Time-weighted average: 15 min.
Immediately dangerous to life An atmosphere that poses an immediate threat to life, would cause irreversible adverse
or health limit (IDHL) health effects, or would impair the ability to escape from the atmosphere. Also, the
1 × 10-1 3 × 10-3 7 × 10-1
maximum level to which an unprotected worker can be exposed for 30 min without
experiencing escape-impairing or irreversible health effects.
Vapor Screening Level
The concentration of a chemical agent in a headspace below which the materiel can be
1 VSL 1 × 10-4 1 × 10-5 3 × 10-3
treated as uncontaminated and workers can work with only a slung protective mask.
Acute Exposure Guideline Levelsa
1-hr AEGL-1 The airborne concentration of a substance above which it is predicted that the general 2.8 × 10-3 1.7 × 10-4 6.7 × 10-2
population, including susceptible individuals, could experience discomfort, irritation, or
8-hr AEGL-1 certain asymptomatic nonsensory effects. However, the effects are not disabling and are 1.0 × 10-3 7.1 × 10-5 8.0 × 10-3
transient and reversible upon cessation of exposure.
1-hr AEGL-2 The airborne concentration of a substance above which it is predicted that the general 3.5 × 10-2 2.9 × 10-3 1.0 × 10-1
population, including susceptible individuals, could experience irreversible or other
8-hr AEGL-2 serious, long-lasting adverse effects or an impaired ability to escape. 1.3 × 10-2 1.0 × 10-3 1.3 × 10-2
a
The acute exposure guidelines (AEGLs) are a hazard communication measure developed by the National Advisory Committee to establish acute exposure
guideline levels for hazardous substances. The committee developed detailed guidelines for devising uniform, meaningful emergency response standards for the
general public.
SOURCE: Adapted from U.S. Army, 2008; U.S. Army, 2011a; NRC, 2005d.
OCR for page 15
BGCAPP AND PCAPP DESIGNS AND PROCEDURES 15
TABLE 2-3 Release Levels, Based on AEL Values, for Reuse of Items
Classification Levela Vapor Screening Health-Based Risk
Level Analysis Requiredb
Contaminated Do Not Release; specific 1 VSL No
safeguards required
Release to Agent Workers Clean Restricted <1 VSL Yes
Release to Nonagent Workers Clean Restricted <1 WPLc,d Yes
Unrestricted Release to Public
<1 GPLd Yes
(Clean Unrestricted)
Never Contaminated Clean N/A Yes
a
Restrictions may preclude disassembly or applying heat or friction (such as grinding) without special
controls.
b
Health-based criteria/risk analyses allow for other methods to be used or developed to determine
which classification level applies.
c
Restricted Maintenance or disassembly of items will only be done by personnel knowledgeable in
agent symptoms and characteristics, and in facilities equipped with appropriate safeguards to control
potential hazards.
d
Unrestricted Items have been previously disassembled and are clean so that they can be released to
the worker population without risk of agent release. Release must be in accordance with an approved
decontamination plan.
SOURCE: Jeffrey Kiley, CMA, "Monitoring Concepts for Site Closure," presentation to the 11th
International Chemical Weapons Demilitarisation Conference and Exhibition, May 2009.
It is also worth noting that the vapor screening methods described above do not
directly measure the amount of chemical agent contaminating solid waste or structural
surfaces. Vapor screening detects the gas phase concentrations of the relevant chemical
agents, which for significant amounts of neat liquid or solid agent are controlled by the
agent's vapor pressure. Vapor pressures are a function of sample temperature; values at
25°C for the chemical agents relevant to the two ACWA site stockpiles are presented in
Chapter 4 (see Table 4-1). Bizzigotti et al. (2009) present temperature-dependent vapor
pressure data for these and other common chemical agents. Detecting a gas-phase agent
concentration equivalent to its vapor pressure in the headspace of an enclosed space
indicates the presence of a reservoir of condensed-phase agent but does not determine
how large that reservoir may be. Operationally, that is not an issue since the VSLs are
many orders of magnitude lower than agent equilibrium vapor pressures, and so obtaining
readings of sub-VSL headspace concentrations is expected to prevent release of any
highly contaminated materials containing significant amounts of liquid or solid agent.
However, the measurement of agent vapor levels well below their equilibrium
vapor pressures may not always indicate very low material contamination levels, because
the effective vapor pressure of any condensed-phase material can be dramatically reduced
if the material is dissolved in bulk liquid or surface liquid layers, if it is physically or
chemically adsorbed onto solid materials surfaces, and/or if it diffuses into and binds to
porous materials (such as activated carbon or concrete). Since the effective vapor
pressure of a specific agent at a given temperature depends strongly on the composition,
OCR for page 16
16 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
morphology, and quantity of the solid and/or liquid substrates it encounters, a given
equilibrated vapor concentration measurement does not necessarily constitute even a
relative measurement of the amount of agent contaminating the condensed-phase
materials within the enclosed space. Adamson and Gast (1997) discuss quantitative
treatments of vapor adsorption and chemisorption by well-characterized condensed phase
surfaces. However, quantitative data for the interactions of chemical agent vapors with
real-world, mixed material surfaces are not available.
Finding 2-1. The prevalent Army demilitarization activity methods of detecting
materials' surface contamination involve enclosing materials and monitoring headspace
agent concentrations. These are indirect methods that can determine if significant levels
of agent are present in the enclosed volume; surfaces are not directly monitored.
However, vapor detection does not identify the location or quantify the level of
contamination on surfaces within the test volume.
The amount and spatial distributions of chemical agent contaminating secondary
waste or structural materials could be determined by direct measurement of adsorbed or
chemisorbed agent on their surfaces. Recent advances in analytical technology have
greatly simplified the rapid and sensitive measurement of the chemical composition of
solid surfaces and matrices. These advances are reviewed and discussed in depth in
Chapter 4. Neither CMA nor ACWA has established a health hazard standard for surface
adsorbed chemical agents, so no agent surface concentration measurement standards are
presented in Table 2-2. However, a recent report from the Centers for Disease Control
and Prevention (CDC), which reviewed the chemical agent monitoring programs at the
final four CMA demilitarization facilities, specifically recommended that CMA develop a
health-based agent hazard level (in milligrams per square meter) for anticipated surface
contamination measurements using surface wipe samples on potentially contaminated
structural surfaces (CDC, 2010). If such a health hazard standard were to be developed
and accepted by relevant regulators, it could be used in conjunction with appropriately
calibrated direct surface composition instrumental measurements to determine if
secondary waste and structural materials are clean enough to be released for disposal. The
CDC suggested that wipe sample evaluations could be used to assess agent contamination
on nonporous materials. As discussed in subsequent sections, the newer direct
composition measurement technologies may also be able to assess contamination levels
of porous materials such as activated charcoal. However, the preparation of accurate
agent-contaminated surface calibration standards using appropriate substrates (e.g.,
concrete, carbon, etc.) is a very challenging task. In the absence of such standards, direct
surface contamination measurements will still produce semiquantitative relative
distributions of surface contamination, which may nonetheless be valuable guides for
material screening and decontamination activities.
OCR for page 17
BGCAPP AND PCAPP DESIGNS AND PROCEDURES 17
Finding 2-2. No CMA or ACWA standards have been established for surface
contamination similar to the airborne agent concentration exposure limits, from which
vapor screening levels have been adopted. If accepted by the CDC and relevant state
regulators, a health-based agent-contaminated surface hazard level measured in mass per
unit area by a new, direct surface contamination measurement technology and suitable
agent-contaminated surface calibration standards could be useful in clearing secondary
waste materials during ACWA disposal operations and/or structural materials during
closure. However, reliable agent-contaminated surface calibration standards may be
difficult to produce.
In the ACWA facilities, all areas through which munitions pass and where agent
could be present at some time will be monitored for airborne agent in NRT using
MINICAMS, and archival data will be obtained with Depot Area Air Monitoring System
(DAAMS) thermal desorption tubes, which are collected for later gas
chromatography/mass spectrometry (GC/MS) analysis in the laboratory. These agent
monitoring methods were described in more detail in the NRC report Monitoring at
Chemical Agent Disposal Facilities (NRC, 2005a).
Work areas in a chemical agent destruction facility are classified by their likely
contamination level using the categories listed in Table 2-4. Worker protection
requirements may vary for a given contamination level, depending on the presence of
liquid agent and the tasks at hand. The requirements for worker protective clothing and
equipment are detailed in Chapter 4 of U.S. Army (2008) and U.S. Army (2011a).
Rooms and corridors adjacent to a Category A or B area are usually classified as
Category C. In Category C or D areas, workers must have a protective mask readily
available in the event of an accidental agent leak. All workers in Category A areas wear
the minimum level of protection required. If liquid agent can be present, then Level A
demilitarization protective ensemble (DPE) suits must be worn. The workers are sealed
into plastic suits made of 20-30 mil polyvinyl chloride (PVC) that completely enclose
them. They don the suits through a slit in the back after which the opening is hermetically
sealed by heat. Inside the suit, they also carry on their back a 10-15 minute supply of air
to be used in an emergency egress. At waist level, there is a fitting on the DPE suit to
attach an umbilical air hose. Workers operate in teams of two in Category A areas. The
team is taxied from the DPE donning area to the point where an entry will be made. A
third worker in Level B protective ensemble remains outside in the entry vestibule in case
of an emergency. As the two workers navigate through the Category A area they plug the
end of their air hoses into the nearest air supply valve, one of many that are installed
throughout the area. The workers can stay in the area for a maximum of 2 hr (U.S. Army,
2008). Before exiting the area they spray one another with decontamination solution to
remove any gross liquid contamination from their DPE suits. Under some conditions,
DPE suits are monitored for agent contamination using a MINICAMS detector with a
sampling wand to determine if decontamination is complete. DPE suits are removed by
cutting them open in the change vestibule. Contaminated suits may be returned to the
Category A area for later treatment. These procedures may vary depending on worker
condition, site operating procedures, and regulations.
OCR for page 18
OCR for page 20
OCR for page 21
OCR for page 24
OCR for page 25
OCR for page 26
OCR for page 27
OCR for page 28
OCR for page 29
OCR for page 30
OCR for page 31
OCR for page 32
OCR for page 33
OCR for page 34
TABLE 2-4 Room Contamination Requirements Using Near-Real-Time Monitoring of the Vapors in the Room
Typical Concentrations Typical Rooms with This Required Protective
Category Definition (AELs) Category Clothing
A A toxic area supported by a cascade IDLH Toxic areas with agent present OSHA/EPA Level A
ventilation in system designated for and access to the atmosphere, protection (typically DPE)
expected chemical agent liquid and/or vapor such as munition breaching areas
under normal conditions
B A toxic area supported by the cascade <1 VSL Explosive containment rooms Typically OSHA/EPA Level
ventilation system designated for expected (ECRs), transfer and holding A, B, or C protection,
chemical agent vapor under normal areas depending on work tasks
situations but expected chemical agent
liquid under off-normal situations.
C An area adjacent to Category A or B areas,
BGCAPP AND PCAPP DESIGNS AND PROCEDURES 19
PUEBLO CHEMICAL AGENT DESTRUCTION PILOT PLANT
The chemical munitions stored at the PCD are artillery projectiles and 4.2-in.
mortar rounds, all of which only contain mustard, a blister agent, in one of two forms,
HD or HT. HD is distilled mustard and HT is a mixture of HD and T, which is essentially
a dimer of H that lowers the melting point of the H. The Pueblo stockpile components are
detailed in Table 2-5. A simplified flowchart for the destruction process is shown in
Figure 2-1. Figure 2-2 is a more detailed flowchart depicting process waste streams and
their disposal. Figure 2-3 displays the site map for the facility.
Pallets containing the projectiles will be transported from the depot's storage
igloos to the munitions storage magazine (MSM) at PCAPP. Because munitions can only
be transported during daylight hours and in good weather, an accumulation of munitions
in the MSM is necessary to ensure round-the-clock operation at PCAPP. The storage
igloos will be monitored for agent vapor before the pallets are removed; agent vapor
levels will also be monitored in the MSM. Munition pallets will again be monitored for
agent vapor before being removed from a transport vehicle after arrival at the unpack area
in the enhanced reconfiguration building (ERB). Projectiles containing bursters will be
moved to the reconfiguration room (Category B level), where the bursters will be
removed by a linear projectile and mortar disassembly (LPMD) machine without
disturbing the burster well that seals in the chemical agent. Uncontaminated energetics
will be sent offsite for processing. Munitions with agent leaks (leakers) will be
overpacked and any agent spills will be documented and decontaminated.
In cases where the burster of a leaker or reject projectile cannot be removed
robotically, the entire munition will be disposed of without disassembling using an
explosive destruction technology (EDT), an ancillary processing system. There are
several types of EDTs, but all involve the destruction of the chemical munitions and their
contents by detonation within an enclosed chamber capable of containing the blast. The
EDT completely destroys both agents and energetics, reducing them to water, carbon
dioxide, and mineral salts. Using an EDT to process problem munitions, such as leakers
and rejects, avoids interfering with the higher throughput achievable for processing
normal munitions through the main PCAPP facility.4
The reconfigured projectiles will then be transported robotically in munition
transfer carts through a long corridor to the agent processing building (APB). In the APB,
the munitions, still containing the burster well that seals the agent within the agent cavity
of the munition casing, will be moved on trays to the munitions washout system (MWS)
in a Category A area. A robot will take a projectile from a tray and place it into one of
several cavity access machines (CAMs) in an inverted position. In the CAM, a hydraulic
arm will dislodge the burster well by ramming it up into the munition casing and
exposing the agent. The agent will then be drained from the munition casing and the
interior of the agent cavity will be washed using a high-pressure water wand on the
hydraulic arm.
The chemical agent removed from the munition will then be transferred to the
agent neutralization system (ANS) area, where it will be neutralized with hot water.
Hydrolysate will not be transferred from the ANS until it has been analyzed and verified
4
A leaker is a munition that has leaked agent. A reject is a munition that for any reason cannot be
robotically disassembled. For more information on EDTs, see NRC, 2006; 2009a.
20 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
TABLE 2-5 Chemical Weapons Stockpile of HD- or HT-Filled Munitions at
Pueblo Chemical Depot
Chemical Fill Energetics
Munition Type (kg) Content (kg) Configuration
105-mm HD, 1.4 Burster: tetrytol, Unreconfigured. Complete
cartridge, M60 0.12 projectile includes fuze, burster.
Fuze: M51A5 Propellant loaded with cartridge.
Propellant: M1 Cartridges packed two per wooden
box.
105-mm HD, 1.4 Tetrytol, 0.12 Reconfigured. Includes burster
cartridge, M60 and nose plug, but no propellant or
fuze. Repacked on pallets.
155-mm HD, 5.3 Tetrytol, 0.19 Includes lifting plug and burster
projectile, but no fuze. On pallets.
M110
155-mm HD, 5.3 Tetrytol, 0.19 Includes lifting plug and burster
projectile, but no fuze. On pallets.
M104
4.2-in. mortar, HD, 2.7 Tetryl, 0.064 Includes propellant and ignition
M2A1 Propellant: M8 cartridge in a box.
4.2-in. mortar, HT, 2.6 Tetryl, 0.064 Includes propellant and ignition
M2 Propellant: M8 cartridge in a box.
NOTE: The M1 propellant present in 105-mm cartridges that have not been reconfigured (as
defined in the column "Configuration") is present in M67 propelling charges--that is, granular
propellant contained in bags as specified in MIL-DTL-60318C.
SOURCE: Adapted from NRC, 2008a.
that at least 99.9999 percent of the agent has been destroyed. The ANS area is classified
as Category A and will be contaminated with agent. The area affected by accidental agent
spills is minimized by the sumps constructed around the CAMs and any other vessel that
contains agent or hydrolysate. Concrete surfaces have a polymer-based coating to help
prevent the agent from being absorbed into them.
From this point on in the process, only residual amounts of agent exist in the
hydrolysate waste stream. The hydrolysate produced from the neutralization of mustard
agent contains thiodiglycol, a major hydrolysis product that must be destroyed to satisfy
the Chemical Weapons Convention. The hydrolysate will be transferred to and treated in
immobilized cell bioreactors, where bacteria will convert the hydrolysate organic
compounds, including thiodiglycol, to water, carbon dioxide, and sludge.5
5
In this context, sludge refers to precipitated solid matter composed of dead microorganisms,
insoluble salts, and other low-solubility materials produced during the bioprocessing of mustard agent
hydrolysate.
BGCAPP AND PCAPP DESIGNS AND PROCEDURES 21
FIGURE 2-1 PCAPP munitions process flow chart. SOURCE: Sean Smith, USAE ACWA Systems
Engineering, "PCAPP Overview," presentation to the committee on February 22, 2011. Note: The numbers
above the boxes are simply sequential indicators that complement the arrows and act as guides for the
multifaceted destruction progression from box to box.
After the agent and any residual solid heel are removed, the projectile bodies
containing the burster wells are placed in other trays and moved to the munitions
treatment unit (MTU), where they will be decontaminated by heating to at least 1000F
for over 15 min prior to being released. The MTU is a long, electrically heated muffle
furnace with a conveyor that will slowly move projectile bodies from one end to the other
as they are treated. The front end of the MTU is in a Category A area, while the back end
is contained in a Category C area. The front end of the MTU will be agent contaminated.
24 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
BLUE GRASS CHEMICAL AGENT DESTRUCTION PILOT PLANT
The chemical munitions stockpile stored at BGAD is more diverse than that at the
PCD. It includes M55 rockets weaponized with GB or VX nerve agents, and several
types of projectiles that contain mustard agent H or GB or VX nerve agents.
Consequently, the process for destroying the munitions in the BGAD inventory is more
complex than the one at PCAPP. The contents of the stockpile stored at the Blue Grass
Army Depot are shown in Table 2-6, and the simplified flowchart for the destruction
process is shown in Figure 2-4. Figure 2-5 presents a more detailed flowchart with the
waste streams and disposal processes indicated. Figure 2-6 displays the site map for the
facility.
The description of the demilitarization process can be separated into two sections:
destruction of the projectiles, which is similar to the PCAPP design (and is for that reason
not repeated here), and the treatment of the M55 rockets.
M55 Rocket Processing
The M55 rockets filled with the volatile nerve agent GB will be the first
munitions to be destroyed at BGCAPP because they pose the highest storage and
processing risks. Each rocket contains about 19 lb of a double-base propellant
(approximately 80 percent nitrocellulose and 20 percent nitroglycerine) and 10 lb of GB.
The rockets will be transported from storage igloos into the unpack area, where personnel
will remove them from the pallets. The rockets will be monitored for agent leaks in the
igloos and again after transportation. (Usually, leaks are vaporized agent.) If agent vapor
is detected outside the firing tube, the rocket is overpacked and returned to storage for
later disposal. Leaker events are documented to inform subsequent decontamination
actions.
The rockets, still contained in their fiberglass shipping and firing tubes (SFTs),
will be placed on a conveyor and moved to the explosion containment vestibule (ECV)
and onto a rocket cutting machine (RCM). First, the propellant motor section at the back
end will be separated from the rocket warhead by cutting through the SFT and rocket
body with a pipe-cutter-like device. The first cut is only deep enough to cut open the SFT
so that it can be removed. Then, the cut will be deepened enough to breach the outer body
of the rocket, allowing the warhead and motor sections to be separated. Uncontaminated
propellant sections and the two firing tube sections will be shipped off-site for disposal.
Up to this point, no agent contamination should exist unless an unexpected event occurs
and the warhead is breached. Thus, the ECV is considered a Category B area.
After separation, the rocket warheads will be transferred to a rocket shearing
machine in the explosive containment room (ECR). The top and bottom of the rocket will
be punctured and the agent is drained. The warhead cavity will then be washed out with a
high-pressure (430 psig) water system to remove residual agent as well as any gelled or
crystallized material that may have formed during storage. The drained warhead will then
be sheared into four segments in the rocket shear machine.
BGCAPP AND PCAPP DESIGNS AND PROCEDURES 25
TABLE 2-6 Description of the Chemical Weapons in the BGAD
Stockpile
Chemical
Munition Type Fill (lb) Energetics Content (lb)
155-mm projectile, H, 11.7 Tetrytol, 0.41
M110
8-in. projectile, M426 GB, 14.4 None
115-mm rocket, M55 GB, 10.7 Composition B, 3.2
M28 propellant, 19.1
115-mm rocket warhead, GB, 10.7 Composition B, 3.2
M56
155-mm projectile, VX, 6 None
M121/A1
115-mm rocket, M55 VX, 10.1 Composition B, 3.2
M28 propellant, 19.1
115-mm rocket warhead, VX, 10.1 Composition B, 3.2
M56
SOURCE: Adapted from NRC, 2008a.
FIGURE 2-4 BGCAPP munitions process flow chart. SOURCE: Darren Dalton, BGCAPP Systems
Engineer, ACWA, "BGCAPP Site Project Overview," presentation to the committee on February 22, 2011.
NOTE: The numbers above the boxes are simply sequential indicators that complement the arrows and act
as guides for the multifaceted destruction progression from box to box.
26 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
Munitions from storage
Projectiles Rockets
Contaminated
Noncontaminated Rocket Cutting shipping and
Dunnage Disassembly rocket motors and Machine firing tubes
shipping and firing tubes (RCM)
Metal Offsite Contaminated
Munitions
parts motors,
Washout System
(MWS) warheads
Energetics
Agent Rocket Shear
Machine
Agent
(RSM)
Energetics,
warhead segments
Agent Energetics
To venturi From Metal Parts Treater
Neutralization Batch Hydrolyzers
venturi (MPT)
Reactors (ANRs) (EBH)
Offgas
Energetics
hydrolysate Clean metal,
glass fibers, Bulk
organic waste Oxidizer
Particulates
Agent
hydrolysate Energetics
Offgas
Neutralization Offsite
System (ENS)
Cyclone
Energetics Offgas
Reactor hydrolysate
Supercritical Aluminum
liners Water Oxidation Filtration
From
(SCWO) venturi System (AFS)
Offgas
Offsite Effluent Water
with agent
Solid Solid to ANRs
waste Filters waste
venturi
Permeate
Effluent
Rejectate
Offsite?
Agent-free
Reverse Energetics Off- water
osmosis Scrubber
water gas Treatment to SCWO Offgas
System (OTE)
Offgas
Secondary Subsequent
waste? treatment Particulate Particulate
Filter Filter
Offgas Offgas
HEPA, activated
charcoal filters
Filter waste,
charcoal
Offsite?
FIGURE 2-5 Process and waste stream diagram for BGCAPP. SOURCE: NRC, 2008a.
FIGURE 2-6 BGCAPP site layout. SOURCE: Darren Dalton, BGCAPP Systems Engineer, ACWA, "BGCAPP Site Project Overview," presentation to
the committee on February 22, 2011.
28 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
After the reverse assembly (i.e., disassembly) is completed, two process streams
are produced (see Figures 2-4 and 2-5):
Agent for processing in the agent neutralization reactors (ANRs)
Energetics for treatment in the energetic batch hydrolyzers (EBHs)
Chemical agent drained from the warhead will be transferred into holding tanks
associated with the agent collection system. Water from rinsing the warhead will be sent
to the holding tank for spent decontamination solution. From the holding tank, the
chemical agent and rinse water are sent to an ANR, where the chemical agent will be
neutralized. The hydrolysate from the ANR will then be sent for treatment to one of three
supercritical water oxidation (SCWO) units, where its organic constituents will be
oxidized to water, carbon dioxide, and salts.
After shearing, each rocket segment will be dropped into a bucket. Sheared
segments will include the burster and the fuze. The buckets will be conveyed to the EBH
room. The three EBHs are large rotating vessels, similar to the drum of a cement mixer
truck, that have discontinuous helical flights used to mix the components as the EBH
rotates.. Once in the EBH room, a robot will pick up each bucket and raise it to a
platform near the top of the EBHs. A second robot will then move the bucket from the
platform to an EBH, where the contents are dumped into the EBH. This area will be
Category A, susceptible to both liquid and vapor contamination.
Prior to the addition of metal parts and energetics, the EBHs are partially filled
with water followed by 50 percent caustic, to produce a concentration of 39.5 percent
caustic, then heated to 240°F. After processing the metal parts and energetics for the
specified time, the direction of rotation of the EBH drum will be reversed, lifting the
metal parts out of the EBH and dropping them onto the vibrating screen belt of a
horizontal conveyor. Any liquid will pass through the screen and be collected. When this
operation is completed, the rotation speed of the vessel will be increased, allowing the
liquid to be removed from the EBH through a wire screen that catches any remaining
solids.
The metal parts from the EBH are sent to the metal parts treater (MPT), where
they will be decontaminated by heating them with superheated steam to over 1000°F for
more than 15 min. After treatment, the metal parts can then be sent off-site for recycling
or to a landfill. The hydrolysate from the EBHs will be sent to one of the three energetics
neutralization reactors (ENRs), where the neutralization is completed. The contents will
remain in the ENR until it has been verified that all energetics and any agent present have
been neutralized. The hydrolysate from the EBHs will then be sent to the SCWO units,
where the products are oxidized to water, carbon dioxide, and salts. The energetics
hydrolysate will be blended with the agent hydrolysate to prevent salt components from
potentially solidifying within the SCWO unit; the blending forms a eutectic that lowers
the melting point of the blended components below the temperature of the SCWO
reactors. The inner liner of the SCWO reactors is made of titanium. For processing the
GB blended feed, this liner is scheduled for replacement every 5 weeks, and for the VX
blended feed, it will be replaced every 2.6 weeks. For the H blended feed, the liner is not
expected to require replacement since the expected replacement interval of 75 weeks for
BGCAPP AND PCAPP DESIGNS AND PROCEDURES 29
this feed exceeds the length of time needed for processing the amount of H mustard
hydrolysate that would be generated at BGCAPP.
Projectile Processing
BGCAPP projectile processing will be similar to the processes used at PCAPP.
The projectiles will be unpacked manually and conveyed into an ECR, where the bursters
will be removed by the two LPMD machines and, if not contaminated, sent to an EBH.6
The munition bodies, still containing their burster wells, will then be moved to the MWS.
The projectile bodies will be processed in an MPT instead of an MTU.7 The process from
this point on will be identical to the process at PCAPP, described above, except that the
hydrolysates will be sent to the SCWO units instead of being sent to bioreactors for
treatment.
DESCRIPTION OF THE HVAC SYSTEMS USED AT BOTH FACILITIES
The committee's statement of task specifically identifies activated carbon as a
major secondary waste for which surface monitoring and analysis for agent
contamination should be considered. This section briefly describes the uses of activated
carbon at BGCAPP and PCAPP, which, in general, are similar to its use at other chemical
agent disposal facilities.
The bulk of the activated carbon to be used at BGCAPP and PCAPP resides in the
filter banks of the plants' cascaded HVAC systems. The HVAC system at each site is
carefully designed to protect workers, the public, and the environment. Ambient air is
circulated through the plant in a cascading manner from areas with no agent
contamination to those with low contamination areas and finally to Category B and A
areas, where the most contaminated plant air is expected. These latter areas are
maintained at the lowest ambient air pressures to prevent backflow to less contaminated
areas. More specifically, in the MDB, cascading air passes first through the Category C
areas, including the observation corridors, then through the vestibules and airlocks and on
to Category B areas, such as the ECR room containing the LPMD, and/or Category A
areas, such as the MWS. The ambient air will be constantly monitored using MINICAMS
and DAAMS tubes as it proceeds through areas of increasingly reduced atmospheric
pressure. Finally, the air moves on to the carbon filter farm and then to the exhaust stack,
leaving the plant. The design of the HVAC system for Category E areas such as the
process control room, the medical facility, and so on, also accommodates carbon filters
6
If the projectile is a leaker or a reject whose burster cannot be removed by the LPMD machines, it
will be overpacked for later disposal processing, possibly by an EDT.
7
The MPT is unique FOAK machinery designed for particular application at BGCAPP; the MTU
to be used at PCAPP is an adaptation of a metal annealing oven or, as previously indicated, a continuous-
belt muffle-type oven with material-handling capabilities at the feed and discharge ends. Additional
information concerning the MPT (and the MTU) can be found in NRC (2008b).
30 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
installed on the air intakes while providing for the maintenance of positive air pressure
within these areas.
The filter farms are identical to those used at the baseline incineration facilities.
The description given here is based on a previous NRC report, Disposal of Activated
Carbon from Chemical Agent Disposal Facilities (NRC, 2009b). An aerial view of a
typical filter farm is depicted in Figure 2-7. A typical farm has eight or nine filter units.
Since the operating schedules for PCAPP and BGCAPP are relatively short, it is expected
that the carbon will not have to be changed out before closure. Also, at BGCAPP only
two units may be used at any one time. Two other units will be used after the first agent
disposal campaign is completed. Figure 2-8 shows a side view of a vestibule with the
doors leading into the spaces between the individual filter banks. Figure 2-9 is a
schematic representation of airflow through a filter unit. The airflow through the unit
takes the following path:
1. Through a coarse 85-micron particulate filter to remove large particulates.
2. Through a HEPA filter to remove any remaining particulates.
3. Through six banks of carbon filters with air spaces between them.
4. Through a second HEPA filter to catch any carbon particulates escaping
from the carbon filters.
5. Through the large induced-draft fan that drives the whole HVAC system
by sucking the air out.
6. Up the exhaust stack and into the atmosphere.
Each filter bank comprises 48 trays weighing about 100 lb each and containing about 48
lb activated carbon. A tray is depicted in Figure 2-10 and the airflow through the tray in
Figure 2-11.
MINICAMS monitor the air between banks 1 and 2, 2 and 3, 3 and 4, and 4 and 5,
as shown in Figure 2-9. Some variations on these procedures may occur after negotiations
with the state regulators. If agent vapor at one STEL (see Table 2-1) were detected
between banks 2 and 3, the carbon in banks 1 and 2 would be immediately replaced.
Banks 3 through 6 are never likely to be contaminated and can probably be disposed of
based on generator knowledge (see Box 2-1), but banks 1 and 2 are likely to be heavily
contaminated before breakthrough. It is not expected that the carbon will ever have to be
changed during the relatively short operations schedule. The carbon may have to be
treated as contaminated waste and be disposed according to the each state's specific
regulations.
The adsorbed agents on the carbon can be analyzed by solvent extraction (EPA,
2007a), followed by GC/MS quantification (EPA, 2007b). Studies indicate that both the
nerve agents, GB and VX, and the mustard agent adsorbed on carbon degrade over time
at varying rates and through different catalytic pathways involving water vapor, which is
also adsorbed onto the carbon (NRC, 2009b). However, without direct analysis, the
carbon must be treated as contaminated. A rapid method of scanning the surface to
indicate the presence or absence of agent would greatly simplify the disposal process. But
its use would have to be approved by state regulators.
BGCAPP AND PCAPP DESIGNS AND PROCEDURES 31
FIGURE 2-7 The nine activated carbon filter units for the MDB HVAC system. SOURCE: NRC, 2009b.
FIGURE 2-8 Vestibule on the side of an MDB HVAC unit. SOURCE: NRC, 2009b.
32 ASSESSMENT OF AGENT MONITORING STRATEGIES FOR BGCAPP AND PCAPP
FIGURE 2-9 Schematic representation of airflow through the six filter banks that make up each MDB
filter unit. Carbon filters each contain 48 filter trays arrayed in six columns and eight rows with each tray
oriented in horizontal position. The 85 indicates 85 percent efficiency for the particulate prefilter; H
indicates HEPA filter; F indicates filter; and C indicates carbon filter. SOURCE: Adapted from NRC,
2009b.
FIGURE 2-10 A filter tray. SOURCE: NRC, 2009b.
Other uses of carbon at BGCAPP and PCAPP involve considerably smaller
amounts; however, these uses produce a wide range of contamination levels. For
example, activated carbon is used in the canisters in workers' protective masks. These
may or may not become contaminated depending on where and how they are used.
Activated carbon is also used in the filters on the venting outlets of the agent collection
system (ACS), where agent drained from munitions is collected before neutralization.
The ACS carbon is expected to become highly contaminated.
Current methods used to assess agent contamination of machinery, equipment,
and waste streams at U.S. Army chemical weapons storage and demilitarization facilities
are discussed in more detail in the next chapter.
BGCAPP AND PCAPP DESIGNS AND PROCEDURES 33
FIGURE 2-11 Airflow path through a filter tray. SOURCE: NRC, 2009b.
BOX 2-1
DEFINITION OF GENERATOR KNOWLEDGE
According to ACWA's Monitoring Concept Plan document, generator knowledge
is defined as follows (U.S. Army, 2011a, p. 56):
Knowledge of the item's operational and contamination history shall be used to
assess and bound the possible agent contamination of a solid or liquid material. The
assessment may be based on factors such as location of the item and its proximity to
agent in the facility, use in the facility's operational processes, and worker knowledge
of the item's history. Generator knowledge shall also use supporting records and
documents to provide relevant historical details for definitive evidence of contamination
assessment. Examples of records for contamination categorization include operational,
maintenance, and/or monitoring documents that describe the system associated with the
item supported (such as airlock and room agent readings, LSS [life support system] air
readings) and any other records that would indicate the potential agent contamination of
the item or material.
