2
BGCAPP and PCAPP Process Descriptions and Secondary Waste Generation

This chapter provides an overview of the processes currently planned to destroy the stockpiles of chemical weapons stored at Blue Grass Army Depot (BGAD) and Pueblo Chemical Depot (PCD). They are presented primarily to indicate how the various waste streams are generated. The description of the process for BGCAPP is organized to take into account the trio of agents and the three munition types that will be processed in several types of munition destruction campaigns. In contrast, the description of the process for PCAPP, where a large number of similar munitions containing only one type of agent will be processed, is largely described in terms of the sequential operations that will be used.

BGCAPP PROCESS DESCRIPTION

Insight into the secondary waste streams that will be produced during operation of BGCAPP can be gained through an understanding of the processes for agent and munitions destruction and the waste materials generated by each of those processes. Different handling approaches are necessary for the various types of munitions that require disposal at BGCAPP. Figure 2-1 provides a flow plan of the BGCAPP processes that reflects the three types of munitions: 1

  • 8-inch projectiles filled with GB and 155-mm projectiles filled with VX;

  • 155-mm projectiles filled with mustard agent H; and

  • M55 rockets (and M56 rocket warheads) filled with VX or GB.

Processing of these munitions is discussed serially in the following sections. In many cases, similar operations are used for all three types of munitions. To avoid repetition, the greatest detail is provided for the processing of the GB- and VX-filled projectiles. Figure 2-1 reflects the BGCAPP design configuration made available to the committee when this report was being prepared.

The stored munitions are first delivered from storage igloos to the unpack area. Before leaving the unpack area, all packing material (dunnage) is removed. In addition to the munitions themselves, there is a substantial amount of nonprocess waste (dunnage and miscellaneous waste) that will contribute to the secondary waste generated and disposed of by BGCAPP. Monitoring is performed during the transport from storage and unpacking operations to ensure the safety of workers in recognition that some of these nonprocess wastes have the potential for being agent-contaminated.

GB and VX Projectiles

Neither the 8-inch GB projectiles nor the 155-mm VX projectiles stored at BGAD are charged with energetics. Hence, separation of the burster from the agent-filled portion of the rounds is not needed (as is the case for the H-filled munitions discussed later). After being unpacked, these GB and VX projectiles are initially sent to the nose closure removal station, where the lifting plugs are separated from the projectile bodies. The lifting plugs are fed to the metal parts treater (MPT), and the projectile bodies are sent to the munitions washout station (MWS) (see Figure 2-2).

At the MWS, agent is accessed by puncturing the projectile bodies, which are then drained by inverting the munitions. The residue remaining in the agent cavity is then washed out with a high-pressure spray nozzle using water at 110°F and 10,000 psig (NRC, 2005b). The rinse-out process is important to remove whatever fraction of the agent may have gelled and cannot be readily decanted from the perforated projectiles. The MWS process generates two process

1

Note that the actual order of the munitions processing schedule calls for all GB munitions to be processed first, followed by all VX munitions and, finally, all mustard agent H munitions. Changeover periods of 12 weeks between processing GB and VX munitions and 20 weeks between processing VX and H munitions are scheduled. Sam Hariri, lead process engineer, BGCAPP, “BGCAPP throughput and availability analysis (TAA),” presentation to the committee, January 23, 2008.



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2 BGcaPP and PcaPP Process descriptions and secondary Waste Generation This chapter provides an overview of the processes Processing of these munitions is discussed serially in currently planned to destroy the stockpiles of chemical the following sections. In many cases, similar operations are weapons stored at Blue Grass Army Depot (BGAD) and used for all three types of munitions. To avoid repetition, the Pueblo Chemical Depot (PCD). They are presented primar- greatest detail is provided for the processing of the GB- and ily to indicate how the various waste streams are generated. VX-filled projectiles. Figure 2-1 reflects the BGCAPP design The description of the process for BGCAPP is organized to configuration made available to the committee when this take into account the trio of agents and the three munition report was being prepared. types that will be processed in several types of munition The stored munitions are first delivered from storage destruction campaigns. In contrast, the description of the igloos to the unpack area. Before leaving the unpack area, process for PCAPP, where a large number of similar muni- all packing material (dunnage) is removed. In addition to the tions containing only one type of agent will be processed, is munitions themselves, there is a substantial amount of non- largely described in terms of the sequential operations that process waste (dunnage and miscellaneous waste) that will will be used. contribute to the secondary waste generated and disposed of by BGCAPP. Monitoring is performed during the transport from storage and unpacking operations to ensure the safety of BGcaPP Process descriPTioN workers in recognition that some of these nonprocess wastes Insight into the secondary waste streams that will be pro- have the potential for being agent-contaminated. duced during operation of BGCAPP can be gained through an understanding of the processes for agent and munitions GB and VX Projectiles destruction and the waste materials generated by each of those processes. Different handling approaches are necessary Neither the 8-inch GB projectiles nor the 155-mm VX for the various types of munitions that require disposal at projectiles stored at BGAD are charged with energetics. BGCAPP. Figure 2-1 provides a flow plan of the BGCAPP Hence, separation of the burster from the agent-filled portion processes that reflects the three types of munitions: 1 of the rounds is not needed (as is the case for the H-filled munitions discussed later). After being unpacked, these • 8-inch projectiles filled with GB and 155-mm projec- GB and VX projectiles are initially sent to the nose closure tiles filled with VX; removal station, where the lifting plugs are separated from • 155-mm projectiles filled with mustard agent H; the projectile bodies. The lifting plugs are fed to the metal and parts treater (MPT), and the projectile bodies are sent to the • M55 rockets (and M56 rocket warheads) filled with munitions washout station (MWS) (see Figure 2-2). VX or GB. At the MWS, agent is accessed by puncturing the projectile bodies, which are then drained by inverting the munitions. The residue remaining in the agent cavity is then 1Note that the actual order of the munitions processing schedule calls washed out with a high-pressure spray nozzle using water at for all GB munitions to be processed first, followed by all VX munitions 110°F and 10,000 psig (NRC, 2005b). The rinse-out process and, finally, all mustard agent H munitions. Changeover periods of 12 is important to remove whatever fraction of the agent may weeks between processing GB and VX munitions and 20 weeks between processing VX and H munitions are scheduled. Sam Hariri, lead process have gelled and cannot be readily decanted from the perfo- engineer, BGCAPP, “BGCAPP throughput and availability analysis (TAA),” rated projectiles. The MWS process generates two process presentation to the committee, January 23, 2008. 0

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 bgCAPP ANd PCAPP PrOCeSS deSCriPTiONS ANd SeCONdAry wASTe geNerATiON Munitions from storage Projectiles Rockets Contaminated Noncontaminated shipping and Rocket Cutting Dunnage Disassembly rocket motors and firing tubes Machine shipping and firing tubes (RCM) Metal Contaminated Offsite Munitions parts motors, Washout System warheads (MWS) Energetics Rocket Shear Agent Machine Agent (RSM) Energetics, warhead segments Agent Energetics Metal Parts Treater To venturi Neutralization Batch Hydrolyzers (MPT) Reactors (ANRs) (EBHs) Offgas Energetics Clean metal, hydrolysate Bulk glass fibers, Oxidizer organic waste Agent hydrolysate Energetics Offgas Neutralization Offsite System (ENS) To Cyclone drums Offgas Filtrate Reactor Supercritical Aluminum liners Offsite Water Oxidation Filtration (SCWO) System (AFS) Offgas Offsite Effluent Solid Solid Filters waste waste venturi Permeate Effluent Rejectate Offsite? To Reverse Energetics Off- Scrubber storage osmosis gas Treatment Offgas water System (OTE) Offgas Secondary Subsequent Particulate Particulate waste? treatment Filter Filter Offgas Offgas HEPA, activated charcoal filters Filter waste, charcoal Offsite? FIGURE 2-1 Process and waste stream diagram for BGCAPP. 2-1.eps

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 reView Of SeCONdAry wASTe diSPOSAL PLANNiNg FIGURE 2-2 Munitions washout system. SOURCE: PMACWA, May 20, 2008. streams: (1) liquid agent and rinse water and (2) solid metal 1999). Secondary reactions of the hydrolysis products, sta- munition casings. In addition, the atmosphere from the MWS bilizers, and impurities form additional chemical products process is filtered by the main munitions demilitarization during VX hydrolysis. Upon verification of 99.9999 percent building heating, ventilation, and air conditioning (HVAC) agent destruction, the agent hydrolysate is transferred to an system, which is discussed later in the process description. agent hydrolysate storage tank, where it is blended with en- ergetics hydrolysate prior to secondary treatment. Additional details on the chemistry and analysis of the hydrolysate are Treatment of Liquid Agent and Rinse Water from the MWS discussed in Chapter 3 and Appendix B. The liquid agent and rinse water from the MWS is sent Secondary treatment of agent hydrolysate is mandated to the agent collection/toxic storage tanks and subsequently by the Chemical Weapons Convention treaty to ensure ir- to the agent neutralization reactors (ANRs), which have been reversible destruction of the chemical agents. The BGCAPP charged with demineralized water and sodium hydroxide to design, as described in the record of decision of February 7, maintain the desired caustic pH level.2 The resulting solu- 2003, incorporates the use of supercritical water oxidation tion, now termed agent hydrolysate, is then transferred to a (SCWO) for secondary destruction of the hydrolysate. SCWO sampling tank, where the contents are analyzed to ensure that essentially mineralizes the organic constituents, effectively at least 99.9999 percent (160 ppb for VX, 75 ppb for GB, degrading any traces of the residual agent and also destroy- and 86 ppb for H) of the agent has been destroyed.3 Hydro- ing hydrolysis products. The SCWO system for BGCAPP is lysis of GB produces isopropylmethyl phosphonic acid and expected to be fairly tolerant in its ability to process hydro- neutralized hydrofluoric acid. The hydrolysis products of VX lysate feed streams containing two or more liquid phases. At are more complex. The principal products from the VX hy- BGCAPP, the feed for the SCWO reactor will be a mixture of drolysis reaction are bis(diisopropylamino) ethanethiol and agent and energetic hydrolysates. The reactor will operate at ethylmethyl phosphonic acid. A less prevalent but compet- a temperature of 1200°F and a pressure of 3,400 psig.4 This ing hydrolysis reaction forms S-2-(diisopropylamino)ethyl environment is highly oxidizing and converts most elements methylphosphonothioic acid, also known as compound EA- to their most stable oxidation states (e.g., carbon is oxidized 2192, which retains much of the toxicity of VX itself (Yang, to form carbon dioxide, hydrogen to form water, sulfur to form sulfates, and so on). However, the caustic hydrolysate 2Sam Hariri, lead process engineer, BGCAPP, “Process design overview,” feed stream is extremely corrosive under SCWO conditions: presentation to the committee, January 23, 2008. 3A destruction efficiency of 99.9999 percent is somewhat higher than the values given; however, these values are used to ensure that the variance 4Sam Hariri, lead process engineer, BGCAPP, “Process design overview,” range in the analyses results is taken into account. presentation to the committee, January 23, 2008.

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 bgCAPP ANd PCAPP PrOCeSS deSCriPTiONS ANd SeCONdAry wASTe geNerATiON Salts can precipitate and plug the SCWO equipment, making oxidizer unit, a cyclone particulate separator, and a venturi scrubber.9 The OTM is a critical system, because its through- maintenance of the reactors problematic. The SCWO system in turn produces its own waste put limits the amount of waste that can be processed per MPT streams, which must be appropriately managed. The ex- batch. Within the flameless bulk oxidizer, heated air and tremely corrosive SCWO environment results in limited life- natural gas are mixed with the offgas to ensure oxidation of times for the SCWO reactor liners, which will likely require the entrained organics. The bulk oxidizer operates at 2000°F, frequent replacement during runs with VX and GB (NRC, with a gas residence time of 1 second to ensure destruction 2005b). Thus, a secondary waste will be produced in the of dioxins and furans. Particulates present in the effluent form of titanium SCWO reactor liners that have experienced from the bulk oxidizer are removed by a cyclone particulate significant corrosion. The SCWO operation produces several separator, and the particles are recycled back into the MPT other effluents. The offgas from the unit is separated from the for further destruction. The gaseous effluent is sent to a ven- turi scrubber, which removes particulate matter >14 µm in liquid stream, and the gaseous effluent is then processed in the HVAC system for the SCWO processing building.5 The diameter and neutralizes the acid gases by caustic scrubbing. condensed-phase SCWO effluents are a mixture of liquid The venturi scrubber also treats offgas from the ANRs and and solid material that flow into the water recovery system the agent hydrolysate storage tanks (NRC, 2005b). The liquid (WRS). The SCWO process also produces salts (e.g., sodium effluent from the venturi scrubber is sent to agent hydroly- sate storage, where it is combined with agent hydrolysate.10 sulfate) that are insoluble in supercritical water but emerge as a slurry and are separated from the liquid in serial multi- However, if agent is detected, then the liquid is recycled to media and canister filters. These filters constitute a secondary the ANRs for further treatment. waste stream. The residual liquid goes to the reverse osmosis Finding 2-1. Continued recycling of the particulates into the (RO) system, which recovers 70 percent of the water. The other 30 percent of the RO separation is a rejectate brine.6 metal parts treater from the cyclone particulate separator of This constitutes a secondary waste stream and may contain the metal parts treater offgas treatment system may cause agent below the detection limit. The RO rejectate brine is solids buildup, which could impede operation of the metal intended for offsite disposal, provided nondetect levels of parts treater. agent can be verified.7 Recommendation 2-1. The operation of the metal parts treater should be modified to avoid solids buildup and the Treatment of Metal Munition Casings attendant creation of a particulate waste stream that could The drained metal projectile casings from treatment impede its operation. in the MWS are decontaminated in the MPT (see Figure 2-3), which will treat wastes both during munitions destruc- The overhead gases from the venturi scrubber are then tion campaigns and during facility closure operations. The passed through an additional particulate filter. The particulate MPT will treat munitions casings and other metal wastes, filter medium constitutes a secondary waste stream from the as well as plastics such as polyvinyl chloride (PVC), teflon, venturi scrubber and is one of the larger secondary waste streams. The filtered venturi offgas is heated to 120oF to butyl rubber, cellulosic materials, sludge, concrete, the lift- ing plugs, wooden pallets, and demilitarization protective lower the relative humidity and then sent to the munitions ensemble (DPE) suits. The objective of MPT treatment is demilitarization building HVAC, where it flows through activated carbon filters.11 to ensure that metal parts and other secondary wastes pro- cessed through it attain a temperature of 1000°F throughout for at least 15 minutes, which will allow their unrestricted mustard agent h Projectiles release or disposal. The same conditions are used at all other chemical weapons destruction facilities to achieve agent The mustard agent H-filled 155-mm projectile rounds decontamination of such materials.8 differ from those filled with nerve agent VX in that they are Offgases from the MPT are sent to the MPT offgas explosively configured (i.e., they contain both the agent fill treatment system (OTM), which consists of a flameless bulk and a burster), and hence the energetics must be separated before the chemical agent fill can be removed for neutraliza- tion. In the BGCAPP design, the burster is separated from 5Sam Hariri, lead process engineer, BGCAPP, “Process design overview,” the main body of the munition, which contains the chemical presentation to the committee, January 23, 2008. 6Sam Hariri, lead process engineer, BGCAPP, “Process design overview,” 9Sam Hariri, lead process engineer, BGCAPP, “Process design overview,” presentation to the committee, January 23, 2008. 7“Nondetect levels” refers to trace (parts per billion) amounts of a particu- presentation to the committee, January 23, 2008. 10Sam Hariri, lead process engineer, BGCAPP, “Process design over- lar agent that may be present but that are below the value of the approved analytical procedure being used for that agent to quantify with precision. view,” presentation to the committee, January 23, 2008. 8See also the discussion on management of scrap metal under environ- 11Sam Hariri, lead process engineer, BGCAPP, “Overview of MPT and mental regulations in Chapter 3. SCWO process design,” presentation to the committee, January 23, 2008.

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 reView Of SeCONdAry wASTe diSPOSAL PLANNiNg Outlet Airlock Main Cooling Chamber Chamber Inlet Airlock FIGURE 2-3 Metal parts treater. SOURCE: NRC, 2008. 2-3 tions (Yang et al., 1997)14 and are effectively dissolved and fill, by the linear projectile/mortar disassembly (LPMD) machine.12 The agent fill is then emptied from the energet- hence removed from the munition bodies by the MWS. The ics-free munition at the MWS. salts produced from mustard agent hydrolysis are primarily sodium chloride, while the offgas contains some minimal amounts of hydrocarbons. Liquids from H-Filled 155-mm Projectiles Following treatment in the MWS, the process at BG- Bursters from H-Filled 155-mm Projectiles CAPP for treating the agent removed from the H-filled 155- mm munitions is identical to that for the VX-filled 155-mm The separated bursters are treated in the energetics batch munitions, with the exception that H is first hydrolyzed using hydrolyzer (EBH) (see Figure 2-4), where hot caustic (50 hot water (194°F) and then treated with 50 percent sodium percent sodium hydroxide) is added to degrade the tetrytol hydroxide (NRC, 2005b). This treatment converts mustard high explosive. The EBH produces solid material, liquid agent H principally to chloride and thiodiglycol; however, energetics hydrolysate, and offgas. The solid product of the the resultant hydrolysate may also contain residual quantities EBH consists of metal from the bursters, which is then heated in the MPT (BPBGT, 2007).15 The decontaminated metal of other chemical compounds that were present in the agent or that are hydrolyzed mustard agent impurities. A fraction of parts constitute a secondary waste that is very similar to the these are characterized as higher molecular weight heels that decontaminated projectile casings described earlier. Gaseous exist in either the solid or the gelled state within the munition effluent from the OTM is likewise treated as described in the (Yang et al., 1997).13 The heels are made up of sulfonium section on GB and VX projectiles. ions formed from dimerization of mustard agent in the muni- 12Sam Hariri, lead process engineer, BGCAPP, “Process design over- 14Yu-Chu Yang, ACWA program, “Chemical compositions of liquid HT, view,” presentation to the committee, January 23, 2008. solid HT, liquid H and solid H,” presentation to the Mustard Working Group 13Yu-Chu Yang, Assembled Chemical Weapons Alternatives program, Meeting, September 23, 2003. 15Sam Hariri, lead process engineer, BGCAPP, “Process design over- “Chemical compositions of liquid HT, solid HT, liquid H and solid H,” pre- sentation to the Mustard Working Group Meeting, September 23, 2003. view,” presentation to the committee, January 23, 2008.

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 bgCAPP ANd PCAPP PrOCeSS deSCriPTiONS ANd SeCONdAry wASTe geNerATiON Offgas treatment duct Inlet chute Ventilation Drum with shroud steam jacket Camera Discharge chute FIGURE 2-4 Energetics batch hydrolyzer. SOURCE: PMACWA, May 20, 2008. Gaseous Effluent from Energetics Processing The energetics hydrolysate produced by the EBH 2-4 consists of a highly alkaline solution containing nitrate, Processing units dedicated to treatment of the projectile nitrite, acetate, and formate salts (and glycerol as well when bursters produce offgas, which is an important effluent stream propellant from M55 rockets [see next section] is being that requires processing. Offgas is produced by the EBH, the processed). After separation of the solids, the energetics ENS reactor, and the bulk oxidizer unit. These three streams hydrolysate is moved to an energetics neutralization system are fed into the energetics offgas treatment system (OTE), (ENS) (BPBGT, 2007).16 It is likely that all energetics will which consists of a venturi scrubber tower system that uses be destroyed in the EBH, and differential scanning calo- acid to remove ammonia. Effluent from the energetics OTS rimetry is to be performed on the energetics hydrolysate includes excess scrubber water, which constitutes a second- once it is in the ENS reactor to ascertain that this is the case ary waste, and offgas. The offgas is sent through a particulate (NRC, 2005b). Once the energetics hydrolysate within the filter, and the particulate filter medium is another secondary ENS has been cleared, it is sent to energetics hydrolysate waste. After the gaseous effluent has traversed a heater and a storage before going through an aluminum filtration system scrubber, a blower forces it through filter banks consisting of (AFS),17 from which the liquid effluent then goes to the activated carbon and a high-efficiency particulate air (HEPA) SCWO reactor. filter, both of which become a secondary waste. GB- or VX-Filled m55 rockets 16Sam Hariri, lead process engineer, BGCAPP, “Process design over- The M55 rockets are filled with either GB or VX and view,” presentation to the committee, January 23, 2008. are configured with the propellant-filled rocket motors and 17The AFS is covered in the next section, on M55 rockets with GB and the rocket warhead. Each rocket is in its own shipping and VX fills.

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 reView Of SeCONdAry wASTe diSPOSAL PLANNiNg FIGURE 2-5 Rocket cutting machine. SOURCE: PMACWA, May 20, 2008. firing tube (SFT) when delivered from storage to the muni- solid and gaseous product streams similar to those described previously.20 tions demilitarization building of BGCAPP. The warhead contains both energetic bursters and chemical agent fill. With After the agent has been drained, the rocket warhead the rocket still in the SFT, the warhead is separated from components are fed to the EBH in a fashion similar to that for the rocket motor by the rocket cutting machine (see Figure the projectiles, bursters, and empty agent cavities. Energetics 2-5), which uses a pipe-cutter-type mechanism to effect the are from the rockets’ warhead segments, burster charge seg- separation. The section of the SFT that houses the warhead is ments, and fuzes, and when necessary, contaminated motor also removed at this point. Noncontaminated rocket motors, segments. The burster energetics for the M55 rockets are which comprise a secondary waste stream, are sent to storage much different from the tetrytol found in the mustard agent for shipment offsite and subsequent disposal. Noncontami- H munitions: They include lead styphnate, lead azide, barium nated SFTs will be disposed of offsite at a Toxic Substances nitrate, antimony sulfide, tetracene, lead azide, RDX, cal- Control Act (TSCA)-permitted commercial facility.18 cium resinate-graphite, and TNT. The propellants are usually The warheads are sent to the rocket shear machine processed separately from other energetics and are expected (RSM) (see Figure 2-6), where they are first punched in the to be effectively hydrolyzed by the EBH. In addition to the top and bottom of the rocket agent cavity to drain the agent, energetics, there will be other materials, including the firing and a high-pressure warm-water stream is used to remove tubes and rocket cavities. any solidified heels or residuals. The agent and washout wa- The operational sequence of the EBH is as follows: ter are then sent to the agent collection storage. The drained Motor segments from contaminated rockets are separated rockets’ warheads (and, where applicable, contaminated from the warhead and tailfin pieces and delivered to an EBH. rocket motors) are then chopped at three additional loca- Then water and a caustic solution are added to the EBH, after tions by the guillotine-like blade of the RSM (NRC, 2005b). which the rocket motor segments are added and processed Process water is used during this cutting. for 2 hours. Warhead and tailfin segments are then added and Only about 200 of the M55 rockets stored at BGAD processed for 4 hours. Undissolved materials consisting of are expected to have rocket motors that are contaminated SFT pieces, burster walls, and metal parts from the rockets with agent due to leakage.19 The motors and warheads of are then removed from the EBH. After all the solids have contaminated rockets are fed to the RSM, where they are been removed, EBH rotation speed is increased to remove sectioned such that they fit into the MPT. The contaminated hydrolysate, which is sent to the ENS reactor. Hydrolysate SFTs are sent to the MPT for further treatment, generating in the ENS reactor is sampled and tested by differential scan- ning calorimetry to verify that organics have been destroyed to acceptably low levels. When the energetic materials are determined to be well below the level at which the hydro- 18The use, storage, and disposal of PCBs are regulated by the Environ- lysate would pose an explosion hazard, the hydrolysate is mental Protection Agency (EPA) under the Toxic Substances Control Act transferred to storage tanks. Metal parts from the EBHs are and 40 CFR, Part 761. PCB waste handlers, including some generators, sent to the MPT, where they are heated to 1000°F for at least transporters, commercial storers, and disposers of PCB wastes, must notify EPA of their PCB waste activities, and each receives a unique identifica- 20At the time this report was prepared, BGCAPP did not have approval tion number. Any PCB disposal facility must obtain approval of the EPA regional administrator for the region in which the facility is located (40 from EPA Region 4 to treat PCBs and is not included under the national CFR 761.77). approval granted by the EPA for the incinerators at the four other stock- 19Roger Dickerman, systemization manager, BGCAPP, “Secondary waste pile disposal facilities under the U.S. Army’s Chemical Materials Agency streams,” presentation to the committee, January 23, 2008. (CMA).

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 bgCAPP ANd PCAPP PrOCeSS deSCriPTiONS ANd SeCONdAry wASTe geNerATiON FIGURE 2-6 Rocket shear machine. SOURCE: PMACWA, May 20, 2008. 15 minutes, then cooled and sent to storage for offsite dis- secondary wastes will be segregated into contaminated and posal. The secondary waste stream that is the solid product noncontaminated materials, as determined by enhanced of the MPT may contain the toxic metals lead, barium, and onsite container monitoring prior to opening. Noncontami- antimony. nated wood pallets will be shipped offsite without treatment Before the energetics hydrolysate is treated by SCWO, for disposal by appropriate methods to minimize waste. All it is first sent to the AFS, where 75 percent phosphoric acid, wood pallets and other dunnage associated with leaking 35 percent hydrochloric acid, and 93 percent sulfuric acid are munitions will be treated as agent-contaminated dunnage added to precipitate the aluminum. The treated rocket com- and will be decontaminated to meet the airborne exposure ponents account for the largest fraction of aluminum-bearing limits (BPBGT, 2004) set in an approved waste analysis plan (WAP) (BPBGT, 2007).22 Additional waste streams include wastes, but energetics hydrolysate from other H-containing rounds is also sent through the AFS.21 Most of the aluminum DPE suits and spent carbon filters from the offgas treatment must be removed before treatment in the SCWO reactor be- described above. Agent-contaminated (i.e., spent) activated cause it generates solids that would precipitate in the SCWO carbon is to be shipped offsite for further treatment and dis- reactor and interfere with its operation. The precipitated posal at a permitted treatment, storage, and disposal facility aluminates are separated by filtration, and the filtrate cake (TSDF). Activated carbon that is not contaminated with residue from the AFS is also a secondary waste. The sepa- agent will be managed by appropriate methods to minimize waste (BPBGT, 2007).23 rated liquid is sent to the energetics hydrolysate blend tank and then to the SCWO reactor for final treatment. PcaPP Process descriPTioN Nonprocess secondary Wastes This section describes the PCAPP process being de- Substantial dunnage will be generated by operation of signed by Bechtel National, Inc., to destroy the chemical BGCAPP. Dunnage includes wood pallets, other combustible weapons stockpiled at PCD according to the configuration solids, and metallic solids. Dunnage and other nonprocess 22Specifically, see Sections 3.1.5 and 4.3 of the cited reference. 21Sam Hariri, lead process engineer, BGCAPP, “Process design over- 23Specifically, see Sections 3.1.5 and 4.3 of the cited reference. view,” presentation to the committee, January 23, 2008.

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 reView Of SeCONdAry wASTe diSPOSAL PLANNiNg information available to the committee when this report was Metal parts such as the projectile casings are treated by being prepared. A process flow diagram is given in Figure being heated in the munitions treatment unit (MTU) to a set 2-7. It is worthwhile noting that PCAPP will process only temperature (at least 1000°F) for a specific duration (at least munitions filled with mustard agent HD or HT. No munitions 15 minutes) to decompose any residual agent and energetics. containing nerve agent are stored at PCD. Most agent-contaminated secondary wastes will be The destruction processes for chemical munitions at treated in an autoclave or supplemental decontamination unit PCAPP will involve (1) transfer and disassembly of muni- (SDU) to destroy the agent. All offgases from PCAPP pro- tions to access the chemical agent and energetic materials, cesses, including the offgases from storage vessels used dur- (2) core processes that destroy the agent, and (3) residuals ing these processes, will be treated to ensure that the offgas treatment processes that decontaminate the munitions bod- streams are at or below regulated levels for agent and other ies and other materials associated with the munitions. These contaminants before release directly to the atmosphere. processes are accomplished in the major steps described in Unless otherwise noted, the following discussion is the following sections. The equipment used for projectile based on the RCRA Stage III, Class 3, permit modification disassembly and removal of the agent is the same as that used request and the associated WAP (PMACWA, 2006). The plan for the mustard agent munitions at BGCAPP. has been filed with, but not yet approved by, the Colorado The munitions are disassembled to separate the agent- Department of Public Health and Environment (CDPHE) as containing portions from the energetic materials and their of the preparation of this report (see Chapter 3 for further associated metal parts. Energetics that are not contaminated discussion of the PCAPP WAP). with agent will be separated and prepared for shipment to appropriate offsite destruction and disposal facilities. Agent energetics removal, Treatment, and shipment is drained from the munition bodies using hot, high-pressure water in the MWS. Contaminated energetics will be de- The projectiles (105- and 155-mm) and 4.2-inch mortar stroyed through an explosive destruction technology (EDT) rounds stored at PCD contain HD and some mortar rounds that remains to be selected.24 contain HT. Some 105-mm projectiles have been reconfig- During disassembly of the munitions, the main waste ured to remove the propellant and fuze but retain a burster streams that call for further processing are as follows: and nose plug. Unreconfigured 105-mm projectiles with integral fuzes and bursters are contained in sealed tubes with • The chemical agent drained from the munition bags of propellant, two tubes to a box. All of the 155-mm cavities; projectiles have been reconfigured to contain lifting plug and • The energetic materials, which may include propel- burster but no fuze. The 4.2-inch mortar with integral fuze, lants, bursters, igniters, and fuzes, and their associ- burster, propellant wafers, and ignition cartridge are con- ated metal parts; tained in sealed tubes, two tubes to a box (NRC, 2005a). • Metal munitions casings and their associated metal The munitions are brought from storage to the energet- parts; ics reconfiguration building (ERB) in overpack (enclosed) • Dunnage, most of which is not contaminated with pallets via the munitions service magazine. The air in each agent; overpack pallet is monitored after transport to determine • Process offgas streams and air from the facility’s whether there are any leaks. If no leak is found, the pallets HVAC system; and are removed from the overpack and moved by a forklift into • Filters used during offgas treatment (carbon, HEPA, the ERB. The pallets are manually unpacked; the boxes of the etc.). unreconfigured 105-mm projectiles and the 4.2-inch mortars are opened; the munitions, contained in sealed fiber shipping In the core disposal operations that follow disassembly, tubes, are then removed from the boxes. The interior of each the chemical agents are destroyed by hydrolysis, which is tube is monitored for agent. If a leak is found, the munitions in turn followed by a secondary biotreatment process in are overpacked and returned to storage for later onsite treat- immobilized cell bioreactors (ICBs) to treat the streams ment by the yet-to-be-selected EDT. Munitions determined resulting from the hydrolysis (the hydrolysates) to meet to be leaking in storage or during transport to the ERB will Chemical Weapons Convention requirements and produce also be processed by the EDT. environmentally acceptable wastes. Munitions that are found not to be leaking are manually removed from the shipping tubes. In the case of the 105- mm projectiles, the propellant bags are separated from the 24An EDT involves using controlled explosive charges in an enclosed munitions. The 4.2-inch mortars are disassembled to remove chamber. There are several versions of this technology. The Resource the ignition cartridge, propellant wafers, and miscellaneous Conservation and Recovery Act (RCRA) permit for PCAPP provides for metal parts. Secondary wastes from this operation will in- the use of an EDT. A forthcoming National Research Council report will examine the applicability of the various types of EDTs for use at PCAPP clude uncontaminated propellant bags and wafers, ignition and, possibly, BGCAPP. The secondary waste from these EDTs is outside cartridges, and miscellaneous metal parts. the scope of this report.

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 bgCAPP ANd PCAPP PrOCeSS deSCriPTiONS ANd SeCONdAry wASTe geNerATiON Dunnage, Offsite metal parts Explosive Contaminated energetics and leakers Munitions Unpack and Offgas, Offsite destruction from storage reconfiguration metal (metal) technology Uncontaminated energetics (EDT) Munitions Contaminated bursters Linear Energetics Energetics/ projectile/ service magazine Offsite propellants Uncontaminated bursters mortar (ESM) disassembly (LPMD) Munitions Vent to MTU offgas treatment system Munitions Munitions Metal (clean washout treatment munitions Offsite Offgas, munitions bodies system (MWS) unit (MTU) bodies) Vent to BTA Agent Offgas offgas treatment system, then to atmosphere Spent Agent Biotreatment decontamination hydrolysis Sludge Offsite area (BTA) Hydrolysate solution reactors To process water system (recycle) Water recovery Solids Offsite system (WRS) To process water system (recycle) Contaminated Brine Supplemental decontamination Clean dunnage and recovery Solids Offsite unit (SDU)/autoclave waste secondary waste area (BRA) Vent to BRA offgas treatment Offgas Offsite system, then to atmosphere Offgas from HEPA and Filter Offsite or munitions venturi Scrubber activated waste autoclave treatment unit charcoal filters Spent Particulates solution To atmosphere Recycle to agent hydrolysis reactors FIGURE 2-7 Process and waste stream diagram for PCAPP. 2-7.eps

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0 reView Of SeCONdAry wASTe diSPOSAL PLANNiNg The previously reconfigured munitions (no fuzes) and drums, and other containers; and dunnage. The SDU is a the partially reconfigured munitions (as described above, large electrically heated chamber approximately 12 feet with fuzes) are moved into an explosive containment room, wide, 6.5 feet deep, and 8 feet high (interior dimensions). where nose plugs, fuzes, boosters, and bursters are removed Once it has been loaded, the operators select the correct op- by the LPMD machine robot. The empty burster well is erating conditions (time and temperature) for the materials. sampled to determine if a leak has occurred; if no leak has The temperature can be varied from 195°F to the design tem- occurred, the bursters and fuzes will be shipped offsite to a perature of 600°F. During treatment, any agent that volatil- commercial TSDF. If a leak has occurred in the burster well, izes but does not decompose is treated in the OTS along with the munitions are overpacked for treatment by the EDT.25 other gases. After the SDU has cooled, the decontamination Munitions that cannot be processed successfully by the level of the treated material is confirmed by monitoring. It is LPMD machine robotthat is, rejectswill be container- then unloaded from the SDU and packaged for offsite ship- ized and treated by the EDT. ment. The monitoring capability of the SDU will be used to The ERB HVAC will be vented downstream of the OTS evaluate some wastes for suitability for offsite shipment. The to the agent filter area (AFA). criterion for reclassification as “clean” for offsite shipment is a vapor screening level (VSL) of less than 1.0, whether determined in the SDU or by container headspace monitoring agent hydrolysis and munitions Body Treatment (PMACWA, 2006).26 A munitions body, having been separated from the The autoclave is another PCAPP component used to energetics, still contains agent sealed in its agent cavity by treat wastes from the same kinds of activities. As this report the burster well. The munitions are next moved to the cav- was being prepared, a descision on which wastes would go to ity access machine in the agent processing building (APB). the SDU and which to the autoclave had still not been made. There, the burster well of each projectile is buckled (or, in The autoclave has a working space approximately 4 feet the case of mortar shells, the mortar base is cut) to access wide, 7 feet deep, and 7 feet high. Once it has been loaded, the agent. The agent is drained and the cavity washed with the operators select the correct operating conditions (time warm, high-pressure water to rinse out any gelled agent or and temperature) for the materials. Air is evacuated during residue. The munitions bodies are then sent to the MTU preheat cycles to promote the vaporization of liquids (BPT, (see Figure 2-8), where they are heated to at least 1000°F 2007). The autoclave is heated by steam at approximately by external heating coils. 350°F to promote hydrolysis of the agent. During treatment, Drained agent, wash water, and any suspended solids any agent that volatilizes but does not decompose, along are fed to agent/water separators. The separated water is with other gases, is treated in the OTS. After treatment, the recycled to the washout station, and the concentrated agent autoclave is cooled and dried by a vacuum pump. If the treat- is sent to a hydrolysis reactor, where it is neutralized with ment is successful, as indicated by monitoring, the material is hot (194°F) water. Hydrolysis is completed by the addition unloaded from the SDU and packaged for shipment offsite. of NaOH. The neutralized solution is then sent to a storage tank, where it will be sampled for the presence of residual oTs and aFa mustard. The clearance criterion is “nondetect,” which is defined as ≤20 ppb for HD and ≤200 ppb for HT. If the batch The purpose of the OTS is to quench and neutralize acid- is not accepted, the hydrolysate is recycled to the hydrolysis ic gases and remove particulates from the offgas streams of reactor. The agent collection and neutralization components the MTUs, the APB tanks, the SDU, and the autoclave. The are vented to the OTS. OTS consists of a venturi scrubber tower, offgas filter, offgas Spent decontamination solution is generated throughout reheater, and offgas blower. Offgases treated in the OTS are the APB for decontamination of equipment and personnel. directed to the AFA for further treatment before discharge The spent decontamination solution is collected in sumps and to the atmosphere. The MTUs vent gases at approximately pumped to the agent hydrolyzers. 650°F. The gases are rapidly quenched by caustic solution to approximately 120°F in the venturi. Some particulates are removed from the gas in the venturi discharge liquid. The sdU and the autoclave The cooled gas and the discharge liquid flow to the scrubber The SDU is used to treat secondary wastes from vari- tower, where the acid gases are absorbed and neutralized by a ous activities, including general maintenance, equipment counterflow stream of water and caustic. The offgas from the maintenance, worker safety measures, and sampling. Typi- SDU and the autoclave are also treated in the scrubber tower. cal secondary waste streams treated are DPE suits and other Spent scrubber liquid (containing particulates) is pumped personal protective equipment; sampling equipment; tools, to the spent decontamination solution tanks. The scrubber offgas is filtered by the offgas filter to remove particulates 25Discussion of PCAPP secondary wastes with Craig Myler, chief 26Specifically, process engineer, Bechtel Pueblo Team, February 12, 2008. see Section C-2b-1, page C-13, of the cited reference.

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 bgCAPP ANd PCAPP PrOCeSS deSCriPTiONS ANd SeCONdAry wASTe geNerATiON FIGURE 2-8 Munitions treatment unit. SOURCE: PMACWA, May 20, 2008. 2-8 Fixed, bitmapped an associated ICB effluent tank, where image will discharge to greater than 0.5 micron. To prevent condensed droplets from the discharge will be sampled to verify the satisfactory entering the offgas blower, the filtered offgas is heated to performance of the biotreatment. Acceptable performance reduce the relative humidity. The blower sends the treated for the biodegradation process is the removal of more than offgas to the AFA. 95 percent of thiodiglycol, with the goal being to remove 99 The AFA is common to the ERB and the APB and con- percent or more of thiodiglycol and an average of 90 percent sists of 10 filter units, 8 in operation and 2 in standby. Each or more of total organic compounds (PMACWA, 2006).27 If filter unit consists of a particulate prefilter, a HEPA filter, an biodegradation is insufficient, the effluent will be recycled to activated carbon filter for removal of agent vapor and volatile the ICB module feed tank for further treatment; otherwise, organic compounds (VOCs), five backup activated carbon the effluent will be discharged to the water recovery system filters in the event of breakthrough, and a final HEPA filter. (WRS). The ICB discharges are gases to the biotreatment Filtered air is exhausted into a common header and ducted to area (BTA) OTS, liquids to the WRS, and secondary waste a common stack. There will be secondary waste in the form solids (sludges and other residues), which will be periodi- of spent activated carbon and filter media. cally removed. The 30-day storage tanks vent through dedicated local Biotreatment activated carbon filters to the atmosphere. The remaining biotreatment tanks, including the ICBs, vent to the BTA Hydrolysate that has been cleared for agent content, OTS. The ICB liquid phase contains odiferous components various condensates, and process water is collected in one of that partition to the gas phase and vent to the BTA OTS. The three 30-day storage tanks. The pH is adjusted with sodium BTA OTS (not shown in Figure 2-7) will have six trains, one hydroxide as needed, and nutrients (principally nitrogen in for each ICB module. The principal components of each train the form of ammonium salts or urea, as well as phospho- are (1) two iron sponge absorbers to remove volatile odorous rus) are added before the hydrolysate is fed to one of six inorganic and organic sulfur compounds such as hydrogen ICB module feed tanks. Each module consists of four ICB sulfide, mercaptans, and thiols; (2) a heater to lower the rela- units. The principal product of mustard agent hydrolysis is tive humidity before the carbon adsorption system; (3) an thiodiglycol, and the ICB system biodegrades thiodiglycol activated carbon system consisting of a prefilter (to remove and other organic constituents to innocuous end products, solid particles in order to extend the activity and life of the principally carbon dioxide, water, sulfate, and other oxidized carbon adsorption bed), two activated carbon filters in series mineral chemicals. to remove potentially odorous gaseous compounds and other Important ICB environmental conditions include nutri- VOCs not removed by the iron sponges, and a final HEPA ent concentration, feed rate, temperature, pH (adjusted with nitric acid or sodium hydroxide), and dissolved oxygen (supplied by compressed air blowers). Each ICB module 27Specifically, see page C-11 of cited reference.

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 reView Of SeCONdAry wASTe diSPOSAL PLANNiNg filter (to prevent carbon particles from escaping the unit); so that carbonate scale does not form and foul downstream (4) an exhaust blower and stack; and (5) two iron sponge process equipment. Feed is conditioned by heating and acidi- absorber condensate pumps to pump condensate to the clari- fying it, followed by steam stripping of the carbon dioxide, fiers of the WRS via the ICB effluent tanks. The BTA OTS noncondensable gases, and some VOCs. The stripped gases produces secondary waste from the iron sponge absorber and are transferred to the BRS OTS, and the liquid effluent is secondary wastes from the prefilter, the HEPA filter, and the transferred to caustic mixing tanks, where the pH is increased activated charcoal filter secondary wastes. by the addition of sodium hydroxide to reduce corrosion in downstream equipment. The effluent from the mixing tanks is distilled in the brine concentrator, and about 80 percent Water recovery and Brine reduction of the fed effluent is distillate transferred to the liquid-phase The cleared ICB effluent is approximately 98 wt per- carbon filter unit and, finally, to the process water tanks. cent water, 0.8 wt percent sodium sulfate, 0.7 wt percent The brine concentrator vapor effluent comprises steam and sodium chloride, and traces of agent impurities and degra- noncondensable gases, which are combined with the steam dation products (PMACWA, 2006). The WRS and the brine stripper overhead and vented to the BRS OTS. The brine con- reduction system (BRS) reclaim water from the biotreat- centrator underflow contains essentially all of the nonvolatile ment system effluent and the blowdown from both the material, salts, residual organic compounds, and suspended cooling tower and the steam boiler. In addition, some pro- solids. These materials are extracted by the evaporator/crys- cess water passes through an RO system to feed the steam tallizer units: Water is transferred to the liquid-phase carbon boilers and munitions washout system; the retentate is fed filters and finally to the process water tanks, noncondensable to the WRS. vapor is transferred to the BRS OTS, and the solids (as a The WRS includes two clarifiers, two thickeners, two slurry) are dewatered to produce a solid cake for shipment filter presses, and auxiliary equipment. The ICB effluent to an offsite TSDF as a secondary waste. is transferred to the WRS clarifiers, where a polymer will In summary, the WRS and BRS produce process water, be injected to provide chemical coagulant for enhancing vapor to the BRS OTS, and secondary waste in the form of removal of suspended solids. The clarified effluent will be a solid cake for shipment to an offsite TSDF. It is planned transferred to the BRS. The clarifier sludge will be pumped that the BRS OTS filter cake will be analyzed for toxicity to the WRS thickeners, where a polymer may be added to characteristic leaching procedure (TCLP) organics (volatile enhance thickening. Thickener overflow is recycled to the and semivolatile constituents) and metals. In addition, the clarifiers, and underflow is pumped to the dewatering filter filter cake is planned to be tested for free liquids to ensure presses. The filter press separates the solids from the liquid the dewatering has removed liquids in accordance with land disposal restrictions (PMACWA, 2006).28 The BRS OTS is, stream. The liquid is recirculated to the clarifiers, and the filter cake, containing 20-25 percent dry weight solids, is a for the purposes of this report, identical to the BTA OTS secondary waste. except that there are no iron sponge absorbers or condensate The BRS includes a feed conditioning system, two brine pumps. The BRS OTS produces prefilter, HEPA, and char- concentrators, two evaporator/crystallizers, two distillate coal filter secondary wastes. liquid-phase carbon filters, three solids dewatering units, 28Specifically, see page C-14. and an offgas treatment system (BRS OTS) (not shown in Figure 2-7). The BRS feed conditioning system converts carbonate salts to carbon dioxide, which is then removed