1
Introduction

The focus of this study is the alternative technologies that might be used to partly or wholly replace or to supplement the U.S. Army's currently planned system to destroy the U.S. unitary chemical weapons stockpile (see Appendix A for the study's full statement of task). 1 This chapter briefly reviews the current U.S. program to destroy its unitary chemical weapons stockpile by incineration, current interest in the alternatives to incineration that might be used, general strategies for disposal of the stockpile, and the scope of the present study and report.

THE U.S. CHEMICAL STOCKPILE DISPOSAL PROGRAM

The U.S. Department of Defense (DOD) is now engaged in a program to destroy the nation's stockpile of unitary chemical weapons through its executive agent for the program, the U.S. Department of Army. The Chemical Stockpile Disposal Program was initiated in 1985, when Public Law (P.L) 99-145 directed that DOD destroy at least 90 percent of this stockpile by September 30, 1994. As the program moved forward, its pace was slower than anticipated, and its date for completion has been revised several times. In 1988, Congress extended the completion date to 1997, and in 1990, P.L. 101-510 extended this date to July, 1999.

The United States and the former Soviet Union (now the Commonwealth of Independent States, CIS) signed a memorandum of agreement on June 1, 1990, to cease chemical weapons production, dispose of inventories, share disposal technology, and develop inspection procedures. In addition, on September 3, 1992, the Conference on Disarmament approved

1  

Unitary chemical weapons contain agents that, by virtue of their molecular composition and structure, are highly toxic and lethal in themselves. Processes to destroy these agents, such as incineration, break down the compounds and convert them into simpler chemical structures that are nonlethal. Binary chemical agents consist of two nonlethal chemicals that, upon mixing, form a lethal chemical agent.



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Alternative Technologies for the Destruction of Chemical Agents and Munitions 1 Introduction The focus of this study is the alternative technologies that might be used to partly or wholly replace or to supplement the U.S. Army's currently planned system to destroy the U.S. unitary chemical weapons stockpile (see Appendix A for the study's full statement of task). 1 This chapter briefly reviews the current U.S. program to destroy its unitary chemical weapons stockpile by incineration, current interest in the alternatives to incineration that might be used, general strategies for disposal of the stockpile, and the scope of the present study and report. THE U.S. CHEMICAL STOCKPILE DISPOSAL PROGRAM The U.S. Department of Defense (DOD) is now engaged in a program to destroy the nation's stockpile of unitary chemical weapons through its executive agent for the program, the U.S. Department of Army. The Chemical Stockpile Disposal Program was initiated in 1985, when Public Law (P.L) 99-145 directed that DOD destroy at least 90 percent of this stockpile by September 30, 1994. As the program moved forward, its pace was slower than anticipated, and its date for completion has been revised several times. In 1988, Congress extended the completion date to 1997, and in 1990, P.L. 101-510 extended this date to July, 1999. The United States and the former Soviet Union (now the Commonwealth of Independent States, CIS) signed a memorandum of agreement on June 1, 1990, to cease chemical weapons production, dispose of inventories, share disposal technology, and develop inspection procedures. In addition, on September 3, 1992, the Conference on Disarmament approved 1   Unitary chemical weapons contain agents that, by virtue of their molecular composition and structure, are highly toxic and lethal in themselves. Processes to destroy these agents, such as incineration, break down the compounds and convert them into simpler chemical structures that are nonlethal. Binary chemical agents consist of two nonlethal chemicals that, upon mixing, form a lethal chemical agent.

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Alternative Technologies for the Destruction of Chemical Agents and Munitions the Chemical Weapons Convention, signed on January 13-15, 1993, by the United States and several other nations, forbidding the development, production, stockpiling, or use of chemical weapons (Gordon, 1992). Language in the convention does not restrict the destruction technology used so long as it converts chemical agents irreversibly to a form unsuitable for production of chemical weapons and so long as it renders munitions and other devices unusable. The convention also stipulates that ''such destruction shall begin not later than two years after this convention enters into force for it and should finish not later than 10 years after entry into force of this convention'' (it does include provisions for individual countries to request a 5 year extension if technical problems are encountered). Upon ratification, the deadline (which supersedes previous deadlines) for stockpile destruction will be December 31, 2004 or later.2 The U.S. chemical weapons stockpile contains two classes of agents, namely, organophosphate nerve agents (sometimes called nerve gas) and blister (or mustard) agents. The nerve agents are usually referred to by their Army code designations: VX, GB (Satin), and GA (Tabun). The blister agents are H, HD, and HT. These agents are contained in a variety of munitions as well as in bulk containers stored at eight continental U.S. sites and at Johnston Island in the Pacific Ocean. As discussed in more detail in Chapter 2, there are about 25,000 total tons of agent in the stockpile (Ember, 1992; Picardi et al., 1991). To put the scale of operations into perspective, about 30,000 tons/year of hazardous waste are incinerated in a typical U.S. hazardous waste incinerator (Vogel, 1989). After testing different disposal technologies in the 1970s, in 1982 the Army chose the approach of component disassembly of the munitions (so-called reverse assembly), followed by incineration and treatment of the off-gases by a pollution abatement system. The bulk storage containers are drained of agent, the agent is destroyed by incineration, and the containers are thermally decontaminated. The NRC's Committee on Demilitarizing Chemical Munitions and Agents reviewed a number of alternative disposal technologies in 1984 and endorsed the Army's choice 2   The 1993 National Defense Authorization Act stipulated a change in the stockpile disposal deadline: "Section 1412(b)(5) of the Department of Defense Authorization Act, 1986 (50 U.S.C. 1521(b)(5)), is amended by striking out 'July 31, 1999' and inserting in lieu thereof 'December 31, 204'."

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Alternative Technologies for the Destruction of Chemical Agents and Munitions (NRC, 1984).3 Recent environmental concerns have prompted the Army and Congress to revisit the topic of alternative technologies (OTA, 1992). The Army's process (hereafter, the baseline technology) is designed as a four-stream incineration process (Figure 1-1). At any given storage site, munitions or bulk containers are transported from storage (in igloos or open storage) to the destruction facility, where they are received in an unpack area. Unpacking munitions, draining agent, and disassembling weapons produces four primary waste streams, namely, dunnage (packing materials), energetics (explosives and propellants), metal parts, and liquid agent. These streams are processed, respectively, in separate incinerators: a dunnage incinerator, a deactivation furnace system (rotary kiln), a metal parts furnace, and a liquid incinerator (see Chapter 4 for details). Because dunnage can be sent to hazardous waste landfills, alternatives to dunnage incineration are not a major focus here. Each of the four furnaces is equipped with an afterburner and a pollution abatement system to dean exhaust gases, which then exit through a common stack. Ventilation air moves from areas of lower to higher potential contamination and, after passing through the disassembly and furnace rooms, is exhausted to the environment after passing through charcoal adsorption beds. The Army's program includes the pilot demonstration of disposal technologies. The Chemical Agent Munitions Disposal System at Tooele Army Depot (TEAD) in western Utah is a pilot plant for production facilities and a prototype of the baseline technology. Research facilities are also located at Edgewood Research, Development and Engineering Center, Aberdeen Proving Ground, Maryland. In the mid-1980s, the Army began constructing its pioneering full-scale facility, the Johnston Atoll Chemical Agent Disposal System (JACADS). JACADS recently completed operational verification testing (OVT), conducted to demonstrate that the baseline technology can safely and effectively destroy the different agents and munitions in the U.S. stockpile while meeting all environmental requirements. OVT is also intended to help identify design improvements to the prototype baseline technology so that appropriate modifications can be introduced before construction and operations begin at the eight mainland sites. P.L. 100456 requires the Army to complete OVT at JACADS before proceeding with equipment tests at 3   A second method, known as the cryofracture process, has also been under development by the Army. In this approach non-bulk munitions are submerged in a liquid nitrogen bath, and fractured in a hydraulic press, and frozen agent and fractured parts are then thermally treated in a single rotary kiln. Both the baseline technology and the cryofracture process end with incineration followed by cleanup of final waste streams. Cryofracture is not reviewed in this report but was the subject of a previous NRC study (NRC, 1991).

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Alternative Technologies for the Destruction of Chemical Agents and Munitions FIGURE 1-1 Schematic of the baseline technology. Source: PEIS (1988).

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Alternative Technologies for the Destruction of Chemical Agents and Munitions other U.S. sites. Construction of full-scale facilities at TEAD is now underway and scheduled to begin operations in 1995 (OTA, 1992; U.S. Department of the Army, 1991). OVT had four campaigns (tests). The first, from July 1990 to February 1991, resulted in the successful destruction of approximately 7,500 M55 rockets containing GB, 77,200 pounds of agent, and 81,600 gallons of spent decontamination solution (Menke et al., 1991; U.S. Army, 1991). Engineering modifications were made during a subsequent shutdown to improve the throughput processing rate. In the second campaign, from October 1991 to February 1992, 13,900 M55 rockets filled with VX were successfully destroyed. In the third, from September to October 1992, 68 ton containers were processed and 113,031 pounds of HD were destroyed. The fourth and final campaign, from September 1992 to March 1993, resulted in the destruction of 105-ram mustard-filled artillery projectiles. Environmental test burns to support the Resource Conservation and Recovery Act (RCRA), the Toxic Substances Control Act (TSCA), and Environmental Protection Agency (EPA) permits were also required for all four furnace systems (U.S. Department of the Army, 1991).4 After the completion of OVT and the receipt of all required permits, JACADS will also dispose of remaining munitions on the island. After each of the four OVT campaigns, the MITRE Corporation prepared separate evaluation reports. A summary report is also available (MITRE Corporation, 1993). The NRC's Committee on Review and Evaluation of the Army Chemical Stockpile Disposal Program will review MITRE's final evaluation of OVT for the Army as part of its ongoing role to provide scientific and technical advice to the Army in carrying out the disposal program. Construction and operation of the disposal facilities at the eight continental sites are scheduled to begin at different times (Table 1-1 shows the schedule as of October 1992). Construction is more than 90 percent complete for most planned facilities at TEAD in Utah. There are uncertainties at some sites. For example, construction at the Newport Army Ammunition Plant in Indiana, scheduled for early 1995, may be delayed pending decisions by the Army and Congress about disposal technologies. Similarly, duration of operations will depend on the amount of agent and types of munitions that have to be destroyed and these vary greatly among sites (see Chapter 2). The greatest duration of operations expected is about 5 years, a relatively short time compared with commercial industrial facilities, which may operate for many decades. 4   RCRA trial bums in the liquid incinerator showed a destruction removal efficiency (DRE) of greater than 99.999999 and 99.99999 percent for VX and GB, respectively, as compared with RCRA requirements of 99.99 percent (SRI, 1992a, b).

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Alternative Technologies for the Destruction of Chemical Agents and Munitions TABLE 1-1 Schedule for the Construction and Operation of Chemical Stockpile Disposal Facilities Installation Construction Systemizationa Operations Johnston Atoll (JACADS) Nov. 1985 Aug. 1988 July 1990-Oct. 1995 Tooele Army Depot (TEAD) Sept. 1989 Aug. 1993 Feb. 1995-Apr. 2000 Anniston Army Depot June 1993 Apr. 1996 Oct. 1997-Nov. 2000 Pine Bluff Arsenal Jan. 1994 Sept. 1996 Mar. 1998-Nov. 2000 Umatilla Depot Activity Jan. 1994 Nov. 1996 May 1998-Dec. 2000 Lexington-Blue Grass Army Depot May 1994 Mar. 1997 Sept. 1998-Feb. 2000 Pueblo Depot Activity May 1994 Mar. 1997 Sept. 1998-May 2000 Newport Army Ammunition Plant Jan. 1995 June 1997 June 1998-Apr. 1999 Aberdeen Proving Ground Jan. 1995 June 1997 June 1998-June 1999 a Testing the facility before operations begin. Source: Program Manager for Chemical Demilitarization, U.S. Army, Aberdeen, Maryland. RISK AND COMMUNITY CONCERNS Risks associated with the storage and disposal of the U.S. chemical weapons stockpile can be classified as follows: health risks to individuals in surrounding communities; risks to workers at military sites in storing or destroying weapons; and risks of the failure of the chosen destruction technology to perform satisfactorily, resulting in shutdowns and delays.

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Alternative Technologies for the Destruction of Chemical Agents and Munitions The first type of risk is critical in the choice of technology. Such risk can itself be broken into several components: risks of agent release from continued storage (from deterioration, sabotage, or accidents); risks of agent release from accidents while transporting agent from storage to destruction site; risks of agent release from unpacking and disassembly operations; risks of agent release during the destruction operation; and health risks related to the discharge of waste streams. This study focuses on the last two specific kinds of risk and the choice of technologies to best address related concerns. Air quality and the health effects of air contaminants are closely related to the choice of destruction technology. The ability of the baseline incineration technology to provide adequate safeguards against air contamination is frequently questioned, which is a principal impetus for this study (OTA, 1992; PEIS, 1988).5 These same concerns might be expressed for any continuous destruction system that produces a large stream of flue gas and in which outlet monitoring cannot ensure against short periods of unacceptable operations. The closed-loop concept, in which all waste streams are stored until chemical analyses have established satisfactory purity, is commonly mentioned as a way of addressing such concerns (OTA, 1992; Picardi et al., 1991). This particular approach, referred to as storage and certification, can be applied to all waste streams, and will be discussed in some detail later in this report. Technologies that greatly reduce or eliminate waste gas discharge from the destruction system offer another way to minimize concern about this potential source of air quality degradation. Risk analyses presented in the Programmatic Environmental Impact Statement (PEIS) focused on catastrophic releases of agent from continued storage or transportation and on the effects of earthquakes and fires on agent storage in the unpack, disassembly, and destruction facilities. In general, this last kind of risk was judged to be less than the risks of transport or long-term storage. These analyses are not directly applicable to assessment of the smaller releases that might occur during disassembly and destruction (PEIS, 1988). Such releases would usually enter the ventilation air streams and could be captured by a properly sized charcoal scrubbing system. Use of charcoal bed adsorption to purify ventilation air is part of the baseline design and, as an 5   A compilation of several hundred statements regarding citizens concerns can be found in the Programmatic Environmental Impact Statement (PEIS, 1988).

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Alternative Technologies for the Destruction of Chemical Agents and Munitions alternative to storage and certification, could be extended to include gas streams leaving the destruction equipment. ALTERNATIVE DEMILITARIZATION SYSTEMS Recent studies of different approaches to the destruction of the Army's unitary chemical weapons stockpile have used the term "alternative technologies," a term reflected in the name of the committee preparing this report. However, most technologies reviewed here or by other investigators are actually unit processes: they represent only part of a system of processes required to demilitarize the U.S. stockpile. For example, separation of agent from munitions and explosives, chemical neutralization of agent, oxidation of the neutralization products, and oxidation of remaining agent on the metal parts are all unit processes, which together might represent an alternative demilitarization system. Alternative demilitarization processes might partly or wholly replace or be used in addition to the current baseline system to handle agent, explosives, propellants, metal parts, dunnage, or any other waste streams potentially contaminated with agent. Chemical weapons demilitarization has been studied and practiced for decades. A National Academy of Sciences (NAS) study in 1969 assessed the hazards of different disposal methods for several types of obsolete and defective chemical warfare stocks: Air Force M34 bomblet clusters containing GB, bulk containers of mustard, M55 rockets containing GB, contaminated and water-filled bulk containers, and drums containing cans of a riot control agent called CS (NAS, 1969). This study advised against then-current plans for ocean dumping, recommending instead that the M34 clusters be disassembled, the withdrawn GB be chemically destroyed by acid or alkaline hydrolysis, and the mustard be burned in government establishments where storage was safe and local air pollution from SO2 and HCl would not be a problem. The report also suggested that a systematic study be undertaken regarding disposal of the chemical weapons and munitions on military installations without hazard to the general population or pollution of the environment. In the early 1980s, alternative approaches to destroy the U.S. stockpile were considered and evaluated by the NRC Committee on Demilitarizing Chemical Munitions and Agents (NRC, 1984). The major alternatives evaluated in this study were placement in the deep ocean, thermal destruction processes such as pyrolysis and combustion, chemical processes, nuclear explosions, and a number of novel methods including in-shell combustion, steam pyrolysis, drain-in-furnace, underground combustion or caustic hydrolysis, and high-temperature pyrolysis. After considering the advantages and disadvantages of each method, the committee concluded that thermal destruction would be preferred for disposal of the U.S. stockpile. Again, this

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Alternative Technologies for the Destruction of Chemical Agents and Munitions conclusion supported the Army's selection of combustion as the most appropriate method. (For a brief review of actual U.S. and foreign experience with chemical demilitarization, see Chapter 3.) As the time to transfer the baseline technology from JACADS to mainland sites has come closer, several national and local organizations and many individuals have voiced opposition to the use of incineration as part of the Army's chemical weapons destruction program (Ember, 1992; OTA, 1992). Discussions with representatives of Kentucky citizens groups concerned about proposed activities at the Lexington-Blue Grass Army Depot led the Office of Technology Assessment to identify the following issues as those generating opposition: concern over possible health risks associated with incinerator effluents, the possibility that the facilities will be used for other types of waste disposal once the stockpile is destroyed, the proximity of destruction facilities to major population centers, and the risk to citizens in communities near chemical weapons storage sites during munitions transport from storage igloos to the on-site incinerator facility (OTA, 1992). The Office of Technology Assessment also briefly addressed some possible alternative technologies, namely, chemical neutralization, supercritical water oxidation, steam gasification (or steam reforming), and plasma arc technology, all of which are also reviewed here. In addressing these and other unit processes that might be applied to stockpile destruction, the committee considered the concerns raised by local communities. As mentioned above, special attention is given here to storage and certification of gas waste streams. In this regard, note that all possible alternative technologies will produce some set of wastes (gas, liquid, and solid) that must be appropriately managed within governing regulatory requirements. In particular, the heteroatoms contained in chemical agents (fluorine [F], chlorine [Cl], sulfur [S], and phosphorus [P]) contribute to the formation of salt wastes that may need disposal in hazardous waste landfills. Opponents of the baseline incineration technology have also claimed that it poses significant risks of exposure to surrounding populations and to the environment, risks that could be reduced by alternative technologies. Greenpeace has sponsored a report reviewing alternatives to incineration for destruction of the chemical weapons stockpile, including biological, chemical, photochemical, electrochemical, and thermal processes (Picardi et al., 1991). These processes would have to be combined to manage the various components of the stockpile. Many of these processes are also addressed here. Finally, Congress has taken a serious interest in the technologies to be used to destroy the U.S. stockpile and is looking to the mandated evaluation of potential alternatives that the Army will submit to Congress by December 31, 1993 (National Defense Authorization Act of 1993). This Army report is required to include an analysis of the present report. Until the Army's report is submitted, the Army may not prepare sites or construct a disposal facility

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Alternative Technologies for the Destruction of Chemical Agents and Munitions based on the baseline technology (with some exceptions noted in the act). The present report provides one basis for the national evaluation of possible alternatives to the baseline chemical weapons destruction technology. TRANSPORTATION OF UNTREATED WEAPONS AND AGENTS The Army previously decided against the transport of the existing untreated stockpiles to one or more central facilities, as documented in the Final Programmatic Environmental Impact Statement (PEIS, 1988). There are also legal and political considerations behind this decision, with states and communities prohibiting transport through their territories. The studies reported in the Army' s environmental assessment recognize that safety hazards and potential environmental impacts would differ for transporting bulk liquid chemical agent and weapons containing chemical agent. The assessment included a feasibility study of shipping ton containers of bulk mustard by sea from Aberdeen, Maryland, to the JACADS facility for destruction in lieu of constructing an incineration facility at Aberdeen. However, this study was never completed, as indicated by a 1987 letter from James R. Ambrose, Under Secretary of the Army, which was included as an appendix to the PEIS (see PEIS, 1988, Volume 3, Appendix S; see also Appendix B of this report). Reasons for not completing this study included the desire to avoid 'further delay in the program, envisioning that the ocean transport alternative would entail lengthy and extensive studies, and the belief that studies of rail transportation would provide a reasonable comparison of the alternatives. However, the letter concluded, "a national programmatic decision does not foreclose subsequent consideration of site-specific alternatives at a later date." Although not convinced that transportation of agents and munitions to one or two major disposal facilities should be excluded from consideration, the committee has not considered such options because they are not within the scope of its study. The alternative of substantially decontaminating chemical weapons and transporting the detoxified material to another site for further destruction is addressed in the next section on strategies for demilitarization. PRIMARY GOALS AND STRATEGIES FOR DEMILITARIZATION The committee believes that in destroying the stockpile safely and expeditiously, the following should be the primary goals of the U.S. Army Chemical Stockpile Disposal Program:

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Alternative Technologies for the Destruction of Chemical Agents and Munitions meet congressionally mandated and international treaty demilitarization and schedule requirements; reduce the risk to nearby communities of agent release from either continued storage or demilitarization operations; ensure acceptable concentration of toxic chemicals in gas waste streams resulting from demilitarization operations; minimize liquid waste disposal problems by minimizing water discharges; and minimize solid waste disposal problems by oxidation or conversion of organic compounds to innocuous forms. At all demilitarization sites, after agents and munitions are removed from storage igloos, transported to the treatment site, unpacked, and disassembled into components, final disposal is necessary. To meet the goals outlined above, the committee delineates two strategies for final disposal, briefly reviewed below. Chapter 8 considers the use of different alternative technologies in these strategies. Strategy 1. On-site disassembly and agent detoxification to a level that meets treaty demilitarization requirements and permits transportation to another site or continued local storage of residues. The Army's current demilitarization program is based on thermal decontamination by incineration to a specified 5X level, that is, treatment at 1000°F for 15 minutes (see Chapter 4 for further discussion), and the release of the dry, solid incineration wastes to commerce for potential metal recovery. An alternative is to disassemble weapons and treat the drained agent to meet demilitarization treaty requirements and to reduce the toxicity for ease of handling, without further oxidation or full mineralization of organic residues.6 Agent could also be fully oxidized with an alternative process. For the first strategy, low-temperature and low-pressure liquid-phase detoxification processes, such as chemical hydrolysis, or liquid-phase processes that completely oxidize the agent could be used. International treaty obligations for demilitarization would be met and the risk from continued agent storage eliminated. Metal parts would be initially decontaminated, to the same end, 6   Mineralization refers to complete oxidation, that is, the breakdown of chemical compounds into basic minerals or inorganic compounds, such as carbon dioxide, water, nitrogen, oxygen, and other gases. For example, the complete combustion of an organic compound, such as agent, results in these primary compounds. If it was desirable to minimize gas emissions, the gaseous carbon dioxide could be captured and converted to solid carbonates.

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Alternative Technologies for the Destruction of Chemical Agents and Munitions with decontamination fluid,7 fluid which is also used to manage spills and dean up work areas, such as the disassembly rooms. Such decontamination fluid contains organic residues, and waste streams generated would be managed according to appropriate regulations. Depending on the process used, this option could entail the storage or shipment of large quantifies of water or the installation of facilities for water removal and purification. Shipment of detoxified material within the existing transportation rules and regulations seems quite feasible, although no specific analysis has been conducted. Sealed shipping containers would be required to prevent the release of any toxic agent that might remain and to conform with the rules for the shipping of toxic chemicals. The risk of transporting detoxified material would be substantially less than the risk of transporting agent. Such liquid-phase detoxification and storage or transport would increase both the volume and mass of the resultant material that requires handling. Transportation costs would probably be high, but they might be offset by decreased facility construction costs (see Appendix C for some discussion of landfill disposal costs). The implications of transport and the disposal rules for the transport of larger quantities of materials should be studied before such an approach is recommended. For some alternatives to agent incineration, such as hydrolysis, very little fixed gas or carbon dioxide would be generated. Gas exhausted to the atmosphere would be reduced or eliminated for this phase of the operation by using these alternatives. Explosives and propellants (energetics), which are present at seven of the nine sites, present special problems. Particularly with the M55 rockets, it is difficult to separate the energetics from agents. Although their temporary storage is feasible and their transportation to another site is possible, local destruction will probably be required. In this process, some evolution of carbon dioxide and fixed nitrogen compounds can be expected. Under Strategy 1, the ventilation air volume for work areas will not substantially differ from that in Strategy 2. Strategy 2. Conversion of agent and disassembled weapons to salts, carbon dioxide, water, and decontarninated metal (mineralization). 7   Initial decontamination is the rapid removal of most of the agent from contaminated surfaces. A decontamination solution used, DS2, is a general-purpose reactive decontaminant composed of 70 percent diethylenetriamine, 28 percent ethylene glycol monomethyl ether, and 2 percent sodium hydroxide, by weight. Final decontamination, to a level allowing release of decontaminated parts to the public, requires a thermal process to the 5X level, as discussed above.

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Alternative Technologies for the Destruction of Chemical Agents and Munitions In Strategy 2, complete oxidation (mineralization) is accomplished without the need for long-term storage of agent, energetics, metal parts, and containers. This strategy meets all goals by oxidation and heat treatment. Agent destruction can be accomplished by a detoxification step, as in Strategy 1, followed by oxidation of the by-products or by direct oxidation as in the baseline technology. Energetics and metal parts are thermally decontaminated. An afterburner would generally be required to ensure complete destruction of all products of incomplete oxidation. SCOPE AND ORGANIZATION OF THE STUDY In response to a request from the Assistant Secretary of the Army for Installations, Logistics and Environment, the NRC formed the Committee on Alternative Chemical Demilitarization Technologies to study alternatives to the baseline technology for the destruction of unitary chemical agents and munitions. The main required steps in the destruction of this stockpile include (1) transport of weapons from storage to the destruction area, (2) unpacking of weapons, (3) disassembly of weapons, (4) destruction of agent and weapons, and (5) waste stream treatment and management. The focus here is on Steps 4 and 5. In particular, the primary task of the committee is to objectively characterize alternative destruction technologies, assess their state of development, identify their advantages and disadvantages for chemical demilitarization, and identify the research and development (R&D) they would require if they were to be used in demilitarization. The committee's charter does not include selecting or recommending any specific technology to the Army (see Appendix A for the statement of task). Results of this study will be used by the NRC's Committee on Review and Evaluation of the Army Chemical Stockpile Disposal Program to generate specific recommendations on disposal technologies. As mentioned above and discussed in more detail later, many of the technologies reviewed here cannot handle all components of the chemical weapons stockpile that must be destroyed. Hence, in its assessment, the committee considered the possible use of individual alternative technologies to demilitarize parts of the stockpile and combinations of technologies to form alternative demilitarization systems. The committee took a number of steps to identify technologies for review. Initially, an attempt was made to list all possible alternative technologies without concern for development status, cost, time required for implementation, suitability, or any other constraint. During this early study phase, the committee used many sources, including prior Army experience, proposals submitted to the Army since 1984, the NRC report Disposal of

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Alternative Technologies for the Destruction of Chemical Agents and Munitions Chemical Munitions and Agents (NRC, 1984), a 1991 report on alternative technologies prepared for Greenpeace International (Picardi et el., 1991), a report by the Scientists Against Nuclear Arms (SANA, 1991), the EPA's Superfund Innovative Technology Evaluation Program (EPA, 1991), suggestions from outside the committee in response to an announcement of the study, and the committee's own suggestions and experience (see Appendix D for committee members' backgrounds). Using all these sources, the committee identified and collected information on technologies that appear to be developed to a point where an assessment can be made. For many of the processes considered, such limited data were available on their use in chemical weapons destruction that assessments of these processes are necessarily highly judgmental. Where the data were dearly insufficient or there appeared to be great constraints on the use of alternatives, these alternatives were not further evaluated. In particular, the committee did not consider the following as viable alternatives: open atmospheric dispersion and/or burning; ocean dumping, including placement in the subducting subsea regions of adjacent plates; placing chemical agent in extraterrestrial orbit; destruction by underground nuclear weapons explosions; burial in volcanoes; destruction of weapons in existing industrial facilities; and minor modifications to incineration systems that have already been reviewed, such as different mechanical configurations of the combustion chamber. All but the last of these concepts was automatically eliminated from further consideration because all require extensive transportation of weapons to disposal sites, a method not within the scope of this study. Some of these methods would also violate environmental regulations. In addition, the Chemical Weapons Convention excludes dumping in any body of water, land burial, and open-pit burning of chemical weapons. The last item in the list above was eliminated because such systems were reviewed in an earlier report on the choice of an incineration system (NRC, 1984). The committee did not develop a numerical rating system for screening criteria but instead established general considerations and requirements to assess alternative technologies (see Chapter 4). Specific information on many of the technologies was provided to the committee by technology developers (see Appendix E). However, in its assessment the committee focused on general approaches rather than specific technologies of specific companies, although it received information from companies on their technologies. (Proprietary information was not used in this study. Some of the processes are

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Alternative Technologies for the Destruction of Chemical Agents and Munitions under intensive development and data concerning their operation are changing rapidly.) The committee held a June 1992 workshop for presentations and discussions on the technologies selected for assessment (see Appendix F on committee activities for a list of workshop presentations). Additionally, a worksheet was developed by the committee for obtaining and organizing important information on each technology (see Appendix G). Invited observers were asked to comment on the formal presentations at the workshop. Observers included technology developers; independent scientists and engineers; members of public interest groups, such as Greenpeace International, Concerned Citizens for Maryland's Environment, and the Kentucky Environmental Foundation; and representatives of federal and state organizations. The committee solicited information in writing from developers working on potentially applicable technologies who were unable to attend the workshop. The information collected, the technical literature, and the committee's own expertise and judgment served as resources in formulating this report. The committee has grouped the processes addressed into preprocessing and postprocessing options, such as charcoal beds (see Chapter 5); low-temperature, liquid-phase processes, such as chemical detoxification reactions (see Chapter 6); and processes at higher temperature and pressure, such as wet air and supercritical water oxidation (see Chapter 7). Chapter 8 integrates and summarizes the information: it summarizes the assessment of the various processes, considers strategies for destroying the chemical weapons stockpile, and delineates how the various unit processes might be applied to the Army's Chemical Stockpile Disposal Program.