Click for next page ( 103


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



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 102
7 Lockheed Martin Integrated Demilitarization System INTRODUCTION AND OVERVIEW The Lockheed Martin Integrated Demilitarization System (LMIDS) was designed by a project team of Lockheed Martin and seven other companies (see Table 1-3~. The LMIDS includes four primary technologies. First, the chemical agent, the energetic materials, and the metal parts are separated via a modified version of the Army's baseline disassembly process. Second, caustic hydrolysis is used to decompose the chemical agent, break down the energetic materials, and decom- pose agent on metal parts and dunnage. Third, the hy drolysates from the hydrolysis processes are further treated using SCWO (supercritical water oxidation). Finally, gas-phase chemical reduction (GPCR) is used to decontaminate the metal parts and dunnage to a 5X level and to treat gaseous effluents from the hydrolysis processes. Table 7-1 describes how these four technolo- gies are used to perform the six primary demilitariza- tion operations described in Chapter 1. The LMIDS segregates the four technologies, as- signing a separate process area for each. Figure 7-1 illustrates how the technologies are linked and shows the basic process flow. The four process areas are: munitions access and energetic deactivation (Area 100) caustic make-up and hydrolysis (Area 200) SCWO (Area 300) GPRC (Area 400) Each of these areas is described in detail in the next section. The technology provider addressed the processing 102 of rockets, projectiles, and mortars but did not explic- itly address the processing of land mines. However, the proposal and the data-gap report included statements that LMIDS could accommodate land mines with mi- nor modifications. DESCRIPTION OF THE TECHNOLOGY PACKAGE Access to Munitions and the Deactivation of Energetics (Area 100) In area 100, the munitions are disassembled, and the chemical agent and energetic components are separated using equipment adapted from the baseline process (see Appendix C). Energetic materials are initially deacti- vated via hydrolysis and metal parts decontaminated with caustic. Rocket Disassembly The delivery of the M55 rockets to Area 100 is iden- tical to the baseline process. Once there, the rockets are unpacked from their pallets and, still enclosed in their shipping/firing tubes, are loaded one at a time nose first through an entry airlock into the rocket demilitariza- tion chamber. Inside this chamber, a hole is punched in the firing tube and rocket, and the agent is drained as in the baseline process. The agent is then pumped into an agent weigh tank to verify the amount drained, and the rocket is sheared into pieces. During the shearing op- eration, the following modification is made to the baseline process: when a shear cut first exposes the propellant, a low-pressure hot-water jet is used to break

OCR for page 102
LOCKHEED MARTIN INTEGRATED DEMILITARIZATION SYSTEM TABLE 7-1 Summary of the LMIDS Approach 103 Major Demilitarization Operation Approach(es) Disassembly of munitions Modified baseline disassembly (multiple lines, modified layout, new drain and wash). Treatment of chemical agent Hydrolysis with caustic; SCWO of hydrolysate; GPCR of off-gas. Treatment of energetics Hydrolysis with caustic; SCWO of hydrolysate; GPCR of off-gas. Treatment of metal parts Wash in caustic; treatment in thermal reactor to SX; GPCR of volatilized materials. Treatment of dunnage Wash in caustic; treatment in thermal reactor to SX; GPCR of volatilized materials. Disposal of waste Solids. Decontaminated metal parts to recycling facility; decontaminated solid residue from GPCR to landfill; salts from GPCR to treatment, storage, and disposal facility (TSDF); solids from SCWO to TSDF; uncontaminated packing materials to landfill. Liquids. None Gases. Gas from GPCR burned in boiler; gas from SCWO released to atmosphere through carbon filters. up and remove the propellant from the interior of the rocket motor casing. Initia/ Deactivation of Rocket Energetics The sheared metal parts, bursters, fuzes, and frag- mented propellant are transported (via gravity feed) into wire baskets in the rocket hydrolysis vessel. The baskets move gradually from the vessel feed point to the discharge point. A 20-percent NaOH solution (caus- tic) at 90C enters near the basket discharge point and flows countercurrent to the basket motion. The caustic is circulated to ensure mixing between the caustic solu- tion and the rocket parts. The caustic dissolves the alu Munitions access and energetic deactivation Area 100) Liquid i Caustic make-up Neutralize and agent , hydrolysis Deactivate ~ Area 200 energetics Off-gas 1 Metal Darts Off-gas , ~ FIGURE 7-1 Process flow for the LMIDS. minum fuze, exposing the energetic materials. The el- evated temperature causes the energetic materials to melt, and these materials are then rendered inert via hydrolysis (see Appendix E for a discussion of the chemistry of energetic hydrolysis). The residence time is set to ensure that when a basket reaches the exit sta- tion, the aluminum in the fuzes has dissolved, and the energetic material has been completely removed from the remaining parts. In the exit station, a gas sample from the vapor space over the basket is analyzed to verify that the agent concentration is below an accept- able level. Isotopic neutron spectroscopy is also used to confirm that no significant amounts of energetics are present. If the results are acceptable, the basket is Carbon filter/vent to atmosphere Water /|~ Super critical water oxidation (Area 300 Hydrolysate Water . I Gas-phase Sa chemical reduction 5X solids to Landfill process recycle/landfill ~~ I (Area 400) Gas hold/test/release To steam boiler as fuel

OCR for page 102
104 ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS moved to the thermal-reduction batch processor in Area 400 for thermal decontamination of the metal parts. Baskets that do not pass this test are returned to the rocket hydrolysis vessel for additional washing. Projecti/e/Mortar Disassembly Mortars and projectiles are delivered to Area 100 in the same manner as they are delivered in the baseline process (see Appendix C). The nose closure, miscella- neous parts, and burster are separated, also according to the baseline process. From this point on, the process differs from the baseline process. Bursters are fed into one of the burster hydrolysis vessels, while fuzes and supplemental charges (if present) are fed into the nose- closure hydrolysis vessel, and nonenergetic nose clo- sures and other miscellaneous parts are collected in baskets for delivery to the thermal-reduction batch pro- cessor in Area 400. The treatment of the energetics is described in the next section. Once the energetic components have been removed, the projectile/mortar is transported out of the explo- sion-containment room and loaded into a special tray. Once the tray is full, it is conveyed into the projectile hydrolysis chamber where the burster wells are re- moved using the baseline approach (although the ma- chine has been significantly redesigned). When the burster wells from all munitions have been removed, the tray is conveyed into the projectile hydrolysis vessel. All operations in the projectile hydrolysis vessel are new. Agent is drained from the projectile bodies by inverting the tray. The drained projectile bodies then undergo initial decontamination by flushing with 90C sodium hydroxide solution to loosen any heels or crys- talline material that may have formed during storage. After flushing, the vapor space is monitored to ensure that the agent concentration is below the level for the 3X standard. If the monitoring produces acceptable re- sults, the tray is sent to the thermal reduction continu- ous processor in Area 400 for further processing. Oth- erwise the flush cycle is repeated. Initia/ Deactivation of Energetics from Projectiles/ Mortars The energetics from the projectiles/mortars include bursters, fuzes, and supplemental charges. The bursters enter the buster hydrolysis vessel from the explosion- containment room via a gravity feed and are contained in a wire basket. A slightly pressurized caustic solution at 135C is constantly pumped through the vessel to facilitate melting, dissolution, and hydrolysis of the energetic material. Multiple bursters can be processed simultaneously, and the basket remains in the caustic solution long enough to ensure that all of the energetic material has dissolved completely. The basket is then raised, allowed to drain, and passed into an airlock where the headspace is tested for agent. Isotopic neu- tron spectroscopy is also used to ensure that no signifi- cant amounts of energetics remain. If the agent concen- tration and neutron spectroscopy results are acceptable, the basket is transported to the thermal-reduction batch processor in Area 400; if not, the basket is returned to the buster hydrolysis vessel. The fuzes and supplemental charges are treated in the nose-closure hydrolysis vessel in the same manner as bursters. The caustic dissolves the aluminum por- tions of the fuzes and exposes the energetic materials. Caustic Make-Up and Hydrolysis (Area 200) In Area 200, chemical agent and energetics are de- activated, separately, by hydrolysis with hot caustic solution in one of several hydrolysis vessels. Hydro/ysis of Drained Chemica/ Agent The chemical agent drained from the munitions in Area 100 is pumped to an agent neutralization reactor in Area 200. The agent neutralization reactor is a 400-gallon, baffled reactor filled with aqueous sodium hydroxide solution (20 percent) heated to 90C. Agent is introduced at a measured rate until the specified agent loading is reached. Agent feed is then switched to an- other reactor. Each agent neutralization reactor is oper- ated in a batch mode and is continuously agitated with two high-efficiency impellers to facilitate the complete hydrolysis of agent. The details of the agent hydrolysis reactions are presented in Appendix D. The hydrolysis reaction mixture is kept at a pH greater than 13 with excess NaOH solution at all times. The batch loading and retention times vary with the type and composition of the materials being neutral- ized. The technology provider's test results for a GB

OCR for page 102
LOCKHEED MARTIN INTEGRATED DEMILITARIZATION SYSTEM loading of about 16.3 wt. percent Produced a destruc . ,,. . lion err~c~ency greater than 99.9999 percent with a re- tention time of two hours, and a destruction efficiency of 99.97 percent for VX after 30 minutes of reaction time, with reactants consisting of mixtures of VX, Comp B. blended propellant powder, and aluminum alloy 6061 T6. (This feed mixture was generated to simulate the feed from M55 rockets.) The agent neutralization reactors and all other neutralization (hydrolysis) reactors are blanketed with nitrogen, and an induced draft fan draws a slight vacuum on the reactor headspace. Off-gases evolved during the hydrolysis process are drawn by the fan through a reflux condenser to condense water vapor and other condensable vapors. The condensate ~ . . . . .. . flows neck Into the reactor, and the noncondensible gases flow continuously to the GPCR reactor Area 400 for further treatment. At the end of the processing period, the reactor's liquid contents are transferred to a holding tank and sampled to ensure that the agent concentration is below the established threshold. If so, the hydrolysate is trans- ferred to a feed tank for SCWO treatment in Area 300. If not, the hydrolysate is recycled to one of the agent neutralization reactors for additional processing. Because GB has been shown to reform at pH below 13 (see Appendix D), excess caustic is used throughout the hydrolysis process to prevent the reformation of agent. Excess caustic is also necessary for the SCWO treatment of hydrolysate to neutralize the acids formed by heteroatoms (e.g., F and C1) during the oxidation process. In the LMIDS, all batch neutralization reac- tors are operated in a staged sequence. While one reac- tor is receiving agent, the second is in the reaction mode, and a third is either being emptied into a hy- drolysate holding tank or being refilled with the caustic decontamination solution. At the end of the neutraliza- tion process, the reaction product (i.e., hydrolysate) is discharged to a holding tank where agent analysis is conducted to ensure that agent concentration require- ments have been met. Agent destruction efficiencies of 99.99 percent are expected for VX by the technology provider, and 99.9999 percent for GB, HD, H and HT. (Note that neutralization followed by SCWO treatment is expected to result in agent destruction to 99.9999 percent and concentration below detection limits.) 105 Hydrolysis of Energetics The caustic solutions from the rocket, burster, and nose closure hydrolysis vessels in Area 100 are con- tinuously fed to an energetics deactivation reactor in Area 200 to ensure that the hydrolysis reactions are driven to completion. (See Appendix E for a detailed discussion of the hydrolysis of energetics.) The ener- getics deactivation reactor is a 9,200-gallon vessel filled with aqueous sodium hydroxide solution (20 per- cent) heated to 90C. The energetics deactivation reac- tor operates in the same way as the agent neutralization reactor. The off-gases are passed through a reflux condenser before being sent to the GPCR reactor in Area 400 for further treatment. The liquid solution is held in the energetics deacti- vation reactor for a specified period of time (to be de- termined). A sample is then taken and tested for agent and energetic residue. If neither agent nor energetic is detected above the target level, the hydrolysate is fed into the feed tank in Area 300 for mixing with agent hydrolysate and treatment by SCWO. If agent or ener- getic is detected above the target level, further reaction time is allowed, and another sample is then taken. Supercritical Water Oxidation of Hydrolysates of Agent and Energetics (Area 300) The LMIDS uses SCWO for the final destruction of the hydrolysis products of both agent and energetics. (The basics of SCWO are described in Appendix F.) The SCWO process in the LMIDS uses a transpiring platelet wall reactor developed and patented by GenCorp/Aerojet and Foster Wheeler. The inner wall of the reactor is formed of layers of porous platelets that allow the continuous transpiration of deionized water at 315C (600F) through the inside wall of the reactor during the SCWO reaction. This inner transpir- ing wall is contained within a conventional outer wall. The injection of transpiration water during opera- tion is claimed to separate the SCWO working fluid, which will be at 780C (1,436F) and 3,500 psi (238 atm), from the inside surface of the reactor, which is kept at the transpiration water temperature of 315C (599F). This reactor technology is purported to have the fol- lowing advantages over conventional-wall SCWO reactors:

OCR for page 102
106 ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS Contact between the working fluid and the reactor wall is reduced, thereby minimizing or corrosion. Deposition of salt on the reactor wall is essentially eliminated. The cooled reactor wall allows higher working- fluid reaction temperatures, reducing the residence time necessary for complete oxidation. The cooler transpiration water (315C versus 780C for the working fluid) is intended to dissolve any inor- ganic salts that reach the reactor wall and carry them to the bottom of the reactor, where, together with the other reactor contents, the reaction mixture is quenched and collected. This design is intended to prevent the depo- sition of inorganic salts and plugging. A schematic dia- gram of the transpiring wall platelet liner is shown in Figure 7-2. Manifold (plenum) At: Hydrolysate (center of annulus) Transpired platelet liner (a) Detailed view of transpired platelet liner Transpiration water 315C Transpiration water 315C 1 1 Cooling water 1 1 r I Plenum | ~ ~ll~lr~lr~ll ~ Heat-up Operating zone Coo~-down \ 2~1/ ~ ~ zone (6 0-78 C) zone Ant . 1~11~l ~p>~p>~ 345CV ~1 1 (b) Schematic drawing of reactor FIGURE 7-2 Transpiring-wall platelet liner. Prior to injection into the SCWO reactor, the agent and energetic hydrolysates are mixed in the SCWO feed tank, heated, and stirred to maintain a uniform solution at 85C. The mixed hydrolysate from the feed tank is pumped up to the operating pressure of the tran- spiring-wall SCWO reactor and mixed with supple- mental fuel (kerosene or isopropyl alcohol) to ensure a high temperature. The hydrolysate/fuel mixture is then heated to 260C by heat exchange with the SCWO re- actor effluent in the hydrolysate feed/effluent heat ex- changer, and the mixture is fed into the SCWO reactor. Compressed oxygen is preheated to 205 C and fed con- currently to the reactor as the oxidant. The proposed full-scale SCWO reactor is a 12-ft- long, vertical down-flow, cylindrical reactor that pro- cesses about 1,200 lb of hydrolysate per hour. The hy- drolysate/fuel oxidation reaction begins at the reactor inlet at 510C. The oxidation reaction results in tem- peratures of 780C at the top of the reactor and about 620C at the bottom. The reactor is designed to have a total residence time of about 10 seconds. This tempera- ture-residence time combination is believed by the technology provider to be sufficient to oxidize all hy- drolysate organics to the desired destruction level. The oxidation products are quenched at the reactor bottom with a water spray to about 345C. The heteroatoms (C1, F. N. S. and P) in the hydrolysate react with the excess sodium hydroxide to form sodium salts. De- struction efficiencies of 99.9999 percent are claimed by the technology provider for all agent and energetic hydrolysates. The effluent from the SCWO reactor, consisting of gases and liquid with dissolved salts, is cooled in heat exchangers and then Repressurized through a let-down valve to atmospheric pressure for separation of the gases from the liquid brine. The liquid brine is sent to an evaporator for drying. The evaporator steam is condensed and the water recycled as process water. The dried salts, which are sampled and analyzed for hazardous con- stituents in accordance with RCRA requirements, are stabilized off site and disposed of in a landfill. The technology provider claims that the effluent gas stream contains only nonregulated gases, mainly car- bon dioxide, excess oxygen, and a small amount of ni- trous oxide. Small amounts of carbon monoxide and low molecular weight hydrocarbons may also be present. The gas stream is dried and passed through

OCR for page 102
LOCKHEED MARTIN INTEGRATED DEMILITARIZATION SYSTEM carbon bed filters to remove traces of volatile organics, and the final gas effluent is monitored and analyzed for regulated constituents as it is vented to the atmosphere. Gas Phase Chemical Reduction Process (Area 400) The GPCR process developed and patented by ELI Eco Logic is used to eliminate organic chemicals on decontaminated metal parts and dunnage (from Area 100) or in gaseous process wastes or off-gases from the neutralization reactors in Area 200. The GPCR (Area 400) process block consists of three parts: a thermal-reduction batch processor; a ther- mal-reduction continuous processor, where applicable; and a GPCR reactor. The thermal-reduction batch pro- cessor is a large vessel that will be loaded with poten- tially contaminated metal parts (such as pieces of sheared M55 rockets and projectile/mortar casings that were not dissolved in the hydrolysis step), other metal parts, and dunnage. The inlet door is opened, and bins containing the solids are conveyed into the thermal- reduction batch processor chamber. After the inlet door is sealed, nitrogen is introduced to purge oxygen. This nitrogen purge gas is vented through carbon filters. The chamber is then heated until the lowest temperature recorded on the load is 538C (1,000F) for at least 15 minutes to ensure 5X treatment. The main process in this chamber is the thermal desorption of organic matter. Gases from the thermal-reduction batch pro- cessor are swept to the GPCR reactor. After a batch has been treated, the chamber is purged and cooled with steam, purged with nitrogen, and unloaded. Dunnage that is (or might be) agent-contaminated is washed and immersed in 20 percent caustic solution, loaded into bins similar to those used for processing metal parts, and placed in the thermal-reduction batch processor, which serves as a pyrolysis reactor. The products are hydrocarbon gases, hydrocarbon liquids, silica residue, and carbon soot. The gases are fed into the GPCR reactor, where they are partially converted into reformer gas (a mixture of hydrogen, methane, carbon monoxide, carbon dioxide, and steam). Accord- ing to the technology provider, approximately 10 per- cent of the carbon feed may remain as soot that will require off-site disposal. Other hydrocarbons, such as tars and phenolic compounds, may also be present. 107 At munition depots where processing results in a large quantity of metal parts of a consistent size and shape (for example, projectile parts), a second type of thermal desorption reactor, the thermal-reduction con- tinuous processor, is used. This unit has three cham- bers and operates continuously with a residence time of one to two hours. The first (preheat) chamber has a nitrogen purge to remove oxygen, and the second (pri- mary treatment) chamber operates at 750C with a re- ducing hydrogen atmosphere. The third (exit) chamber is also purged with nitrogen. All three chambers have airlocks. Metal parts, which have been treated to 5X, are quenched to room temperature and disposed of off site. The gaseous effluent from the thermal-reduction batch processor and thermal-reduction continuous pro- cessor, together with the off-gases from the initial mu- nitions access and energetic deactivation step and from the caustic hydrolysis step, are sent to the GPCR reac- tor, the third part of Area 400. In the GPCR reactor, a hydrogen-rich atmosphere is maintained, and organic chemicals are reduced to methane and water. Hydro- gen chloride, hydrogen fluoride, and hydrogen sulfide are also produced when mustard, GB, and VX/mustard are processed. In addition, the nitrogen from the treat- ment of VX forms nitrogen gas and perhaps some am- monia, while the phosphorus forms phosphorus acids. The GPCR reactor operates at a temperature of 850C or above, and the technology provider claims that a residence time of seconds is sufficient for the complete reduction of all organic matter. Catalytic steam reformers supply hydrogen gas to the GPCR reactor by steam reforming of natural gas. Vertical radiant tube heaters with internal electric heat- ing elements heat the inside of the reactor. The gases enter the top of the GPCR reactor, and their tempera- ture exceeds 870C when they reach the bottom. When the gases leave the reactor, they pass through primary and secondary caustic scrubbers to remove acid gases, water, and fine Articulates. Hydroclones are used to remove solids from the caustic scrubbing fluid. The gas stream exiting the secondary scrubber, which is saturated with water at 38C, is a mixture of hydrogen, methane, carbon monoxide, carbon dioxide, nitrogen, and trace light hydrocarbons. To ensure that no agent is present, this gas is stored in a series of tanks, where it is sampled and tested. If the agent concentration is below

OCR for page 102
108 ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS the allowable stack concentration (ASC), the gas is used as an auxiliary fuel for the steam boiler. Process Instrumentation, Monitoring, and Control Conventional monitoring and control of the pro- cesses are used for the proposed system. The process materials (with the exception of agents and energetics), temperatures, and pressures in this technology package are common in other industrial applications where they are routinely monitored and controlled. The usual col- lection of equipment for monitoring temperature, pres- sure, level control, flow, and other parameters normally measured in a chemical plant is used together with the ACAMS and DAAMS equipment developed by the Army. To prevent plugging in the SCWO reactor, the flow of transpiration water, other flow rates, pressure drops, and reactor operating conditions are closely monitored. Feed Streams The teed streams entering the LMIDS are listed by area in Table 7-2. With the exception of the chemical munitions, the materials listed are routinely used in large-scale chemical processes. The LMIDS proposal includes the mass balances for five campaigns a base case and two demilitarization campaigns each for the Blue Grass and Pueblo arsenals. For the purposes of illustration, only the Blue Grass VX base case is con- sidered here. The feed streams will change for the other weapons campaigns at Blue Grass and for the demilita- rization campaigns at Pueblo. In Table 7-2, Areas 100 and 200 have been combined because it was impos- sible from the flow diagrams to determine the split for the use of caustic and decontamination solutions be- tween these two areas. Waste Streams The waste streams for the LMIDS are listed by area in Table 7-3. All solid wastes (other than the metal parts which have been treated to 5X condition) are treated and then disposed of in a hazardous-waste landfill. Ventilation air from contained process areas is passed through carbon filters and monitored for agent before TABLE 7-2 Process Inflow Streams (lb/hr) from Outside the Process for Blue Grass VX Base Case Campaign (14 M55 rockets/hr and 14 M121A1 projectiles/hr) Component Amount AREA 100a + AREA 200b NaOH Decontamination solution NaOH Water NaOC1 Total M55 rockets VX Steel Aluminum Comp B Nitrocellulose Nitroglycerine Dunnage Total M121A1 projectiles VX Steel Comp B TNT Dunnage Total Nitrogen Total areas 100 + 200 AREA 300C Kerosene Oxygen Waste Oils Total area 300 AREA 400d Natural gas Steam Hydrogen Nitrogen Other dunnage Total area 400 Total plant inflow 741 7 126 7 140 140 172 171 45 189 81 308 1,106 84 1,262 34 4 74 1,458 652 4,203 114 1,074 14 1,202 472 557 s 25 151 1,210 6,615 amunitions access and energetics deactivation bcaustic makeup and hydrolysis Csupercritical water oxidation dgas phase chemical reduction Source: Lockheed Martin, 1998. release. There are no liquid effluents other than rainfall runoff and cooling water (which will not be in contact with hazardous materials). The six waste streams pro- duced by the process are listed below:

OCR for page 102
LOCKHEED MARTIN INTEGRATED DEMILITARIZATION SYSTEM TABLE 7-3 Process Outflow Streams (lb/hr) to the Environment for the Blue Grass VX Base Case Campaign (14 M55 Rockets/hr and 14 M121A1 projectiles/hr) Component Amount AREA 100a AREA 200b AREA 300C Vent gas Treated solids to landfill Total Area 300 AREA 400d Treated metals Steel Other Clean solids to landfill Product gas to boiler Total Area 400 Total plant outflow o o 1,107 1,559 2,666 1,421 11 313 2,183 3,928 6,594 amunitions access and energetics deactivation bcaustic makeup and hydrolysis Csupercritical water oxidation dgas phase chemical reduction Source: Lockheed Martin, 1998. . The SCWO off-gas is continuously monitored, passed through carbon filter beds, and then re- leased to the atmosphere. This gas stream is ex . . . . . a, pectea oy tne technology provider to contain mainly carbon dioxide, oxygen, nitrogen, small amounts of water vapor, and trace amounts of ni- trous oxide and light hydrocarbons. Treated ventilation air from the process contain- ment areas is passed through carbon filter beds. Decontaminated metal parts that have not dis- solved in the hydrolysis reactors are processed to a 5X condition in the GPCR reactor. Sodium salts produced from elements in agent and energetics hydrolysates (fluoride, chloride, sul- fate, nitrate, nitrite, and some phosphate salts) are fed to the SCWO reactor. Tests show that the salts contain up to 10 ppm of organic materials, princi- pally acetone and acetic acid. According to the technology provider, the salts will be free of agent and contain no CWC Schedule 2 compounds. Chemical agents will yield a large amount of salt (VX will yield salt equal to about 150 percent of its original mass). The yield of solid salts from the . 109 energetics will vary with the energetic but will be approximately equal to the weight of the energetic. Salts from the SCWO process will be sent off site ~ . .. . . . . for stao~zat~on ana placement In a hazardous waste landfill. Residues of carbon (e.g. char and soot) and silica will contain traces of hydrocarbons from GPCR processing of dunnage, fiberglass shipping and fir- ing tubes, DPE suits, etc. are shipped off site for disposal in an approximately permitted landfill. GPCR off-gases that contain low molecular weight hydrocarbons (methane and ethylene) and small amounts of hydrogen chloride and hydrogen sulfide are passed through an activated carbon fil- ter and a caustic scrubber and then burned in the facility boiler after passing through a hold-test- release cycle. Noncontaminated dunnage, such as the wood and wood pallets used to package munitions, will be trans- ported off site for reclamation or disposal. Start-up anti Shutdown The LMIDS uses both batch and continuous pro- cesses operating in series (i.e., feeding one another). Standard chemical-industry practices (operation, in- strumentation, and control) can be used to implement normal start-ups and shutdowns, as well as emergency shutdowns. The technology provider has also provided a plan for final shutdown, which includes disassembly of all equipment except the GPCR, treatment of all other process equipment in the GPCR reactor to the 5X standard, and the removal of all equipment from the site. EVALUATION OF TH E TECH NOLOGY PACKAG E Process Efficacy Effectiveness of Munitions Disassembly Rockets. The punching and shearing processes for the rockets are typical of baseline operations and should be capable of achieving the desired processing rates. A unique feature of this technology package is the use of a gravity feed to drop sheared rocket parts into baskets

OCR for page 102
110 ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS submerged in the rocket hydrolysis vessel through a chute and gate. This interface must be capable of (1) withstanding explosions to protect the rocket hydroly- sis vessel or disassembly equipment and (2) operating reliably in the presence of caustic vapors. This opera- tion should be designed to avoid increasing mainte- nance requirements and, thus, reducing the munition throughput rates. Projectiles/Mortars. The initial disassembly ~ro- cesses for projectiles are identical to the baseline pro- cesses and should meet reliability and production ob- jectives. Modifications to segregate and feed the various projectile/mortar parts to the downstream pro- cesses involve multiple, remotely-operated interfaces with the hydrolysis processes. Here, as in the rocket disassembly process, initial reliability may be a prob- lem because of the action of caustic vapors. Another potential problem to achieving the desired throughput without increasing maintenance in DPE suits is the seg- regation of products from the projectile/mortar disas- sembly process into four streams. Safety and reliability problems could arise if the parts, similar in size but different in characteristics, are intermixed. Effectiveness of Agent Decomposition via Hydrolysis Decomposition with caustic is a proven process for bulk agent (see Appendix D). However, because of the complexity of scaling up mixing processes and the dif- ficulty of removing agent from the crevices in sheared rocket parts, the time required to lower the concentra- tion of agent to the required levels in the various plant- scale hydrolysis vessels may be longer than anticipated. A longer residence time would require equipment modifications to achieve the design throughput. Ad- dressing this concern will require testing with near pro- duction-scale equipment. Significant DPE maintenance may be required for the carts used to convey metal parts into the rocket hydrolysis vessel bath and for the pro- jectile baskets that will invert the casings and position them over wash-out wands in a caustic spray environ- ment using remotely operated equipment. However, the committee believes that with a careful design and well chosen materials of construction, the processing objec- tives for the hydrolysis of agent on projectile/mortar parts should be achievable. Effectiveness of Energetics Decomposition via Hydrolysis Significant unknowns remain in the decomposition and deactivation of energetic materials by base hy- drolysis (see Appendix E), and the destruction of ener- getics in the rocket, burster, and nose closure hydroly- sis vessels may take longer than expected because of the uncertain reaction rates. Aluminum rocket parts will also be dissolved in caustic in the rocket hydrolysis vessel. The committee is concerned that the exothermic reaction of aluminum with caustic could produce hot spots and very rapid reactions. The aluminum reaction also produces hydro- gen, which could increase the explosion hazard. The technology provider will have to design and operate the rocket hydrolysis vessel purge-gas and off-gas han- dling systems with these possibilities in mind. Effectiveness of Supercritica/ Water Oxidation The SCWO process appears to be capable of com- pleting the destruction of both agent and energetics. Mustard does contain volatile low molecular weight chlorinated hydrocarbons that can be difficult to treat. These are expected to be oxidized by SCWO but this will have to be demonstrated. A key area of uncertainty in the technology provider's proposed application of SCWO is the proprietary transpiring wall tubular reactor. Although this concept should be capable of achieving the desired processing rates, there has been no long-term experience using a tran- spiring wall in the severe operating environment of the SCWO reactor. Current experience relates almost entirely to much larger diameter, non- transpiring wall reactor vessels and shows that plug- ging and corrosion are the main problems encoun- tered. The technology provider proposes using the transpiring wall to overcome these problems, but this technology has not been demonstrated in ex- tended runs, which will be essential to proving the efficacy of this crucial step in the agent/energetics destruction process. The technology provider will also have to verify that the use of the transpiring wall does not allow waste materials to bypass the reaction zone via the cooler transpiration-water reg- ion adjacent to the wall.

OCR for page 102
LOCKHEED MARTIN INTEGRATED DEMILITARIZATION SYSTEM Effectiveness of Decontamination of Meta/ and Other Munitions Parts Although the GPCR process as proposed has not been applied to metal parts from hydrolysis reactions, prior experience in other applications indicates that this technology should achieve the desired process through- put and decontamination levels. The nature of the par- ticulates produced by the hydrogen reduction of or- ganic materials and salts on the surfaces of metal parts is one area of uncertainty that should be addressed in subsequent testing. These particulates may have char- acteristics (e.g., the formation of sticky soot) that will increase maintenance requirements. Effectiveness of Decontamination of Other Contaminated Materials The nature of the particulates generated from the decomposition of fiberglass rocket shipping/firing tubes, DPE suits, and other organic wastes is still un- certain. Approximately 10 percent by weight of the carbon feed is expected to remain as soot, and the tech- nology provider expects that this solid waste stream will be disposed of off site. The large amount of soot generated in the thermal-reduction batch processor could lead to buildups in gas recirculation paths, which could restrict throughput and require additional main- tenance to clear the gas path. Sampling and Analysis Sampling and analysis requirements appear to be reasonably well known for this integrated process. Easy evaluations of the composition of the hydrolysate can be made from the hydrolysate feed tanks to the SCWO. Similar observations can be made for solid wastes that cannot be released until agent concentrations in adja- cent gas spaces are below allowable levels. The tech- nology provider will also have to ensure that agent does not condense, adsorb, or otherwise accumulate on the internal surfaces of the GPCR off-gas hold-test-release tanks, where it would not be detected in the gas analy- sis but could subsequently revaporize upon depressur- ization and venting to the boiler fuel system. (The same problem exists for all gaseous hold-test-release systems that are subject to significant pressure variations.) 111 Maturity Disassembly Process. The LMIDS uses much of the baseline disassembly process that has been proven at the Johnston Atoll and Tooele, Utah, demilitarization facilities. Modifying the process to include a wash-out step is based loosely on ton-container wash-out tests for the Aberdeen and Newport sites; however, the spe- cific design modifications have not been tested. One of Lockheed Martin's partners, Aerojet, has more than 30 years of experience with hydromining rocket propellants. Interfaces between the disassembly process and downstream processes may limit the throughput be- cause the reliability of the remotely operated handling equipment used for the interfaces could be difficult to maintain. Some of this equipment is new or has never been used in the harsh environment of caustic hydroly- sis processes. Materials selection and design of this equipment will be very important. Agent Hydrolysis. Neutralization is a proven tech- nology for the deactivation of chemical agents (see Appendix D), and agent hydrolysis processes for HD and VX are being implemented at Aberdeen and New- port. Hydrolysis for GB has been done on a large scale at Rocky Mountain Arsenal. Therefore, the hydrolysis of agent is a mature and well tested technology that requires simple engineering and control. Energetics Hydrolysis. Several issues remain to be addressed about the technology provider's implemen- tation of hydrolysis for energetics. The caustic hydrolysis step is intended to dissolve the aluminum fuze and expose the energetic ma- terials. The dissolution of aluminum will result in an exothermic generation of hydrogen gas that will bubble out of the aqueous alkaline solution. The production rate of hydrogen and the release rate of thermal energy will have to be monitored and controlled to ensure that there is no possi- bility of ignition. Also, an autocatalytic redox re- action could occur when the wet aluminum is in the presence of damp energetic materials. There- fore, both must be destroyed in the hydrolysis. 2. Many of the hydrolysis vessels for energetics in- volve mechanical conveyors operating in a hot 20-percent caustic solution, which is a severe

OCR for page 102
112 ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS environment for this type of machinery. There- fore, a great deal of maintenance (by personnel in DPE suits) may be required to keep this equip- ment in operation. No information has been pro- vided to the committee on the reliability of this equipment in a hot caustic environment. 3. The required residence time in the hydrolysis re- actors is directly related to the size of the sheared pieces. The size of these pieces will have to be accurately characterized because they will affect the design of the hydrolysis reactors for energetics. SCWO. The SCWO process for the treatment of VX hydrolysate has been extensively examined in a previ- ous NRC study (NRC, 1998), and work on the use of SCWO to treat hydrolysates from agent and energetics destruction is ongoing. Other SCWO systems have been under development for more than 20 years; the Huntsman Corporation of Austin, Texas, for example operates the only commercial SCWO unit for the treat- ment of organic-laden wastewater. Nevertheless, corrosion, erosion, and plugging problems in the presence of salts. This technology has not been used with salt-containing supercritical water. 3. Control of the transpiring-wall reactor may be dif- ficult, and its operation may be very sensitive to system fluctuations. Fluctuations in pressure can cause a backflow into the transpiring wall and plugging. 4. Because the SCWO reactor is a unique and un- proven piece of equipment in the LMIDS, main- tenance may be difficult. Furthermore, because of the difficulty of construction, if the reactor be- comes nonoperational, there may be a significant delay before it can be repaired or replaced. 5. The SCWO reactor would be used with a mixture of energetics and agent hydrol~sates. Because SCWO is capable of treating a variety of materi- als (probably simultaneously), this may not be a problem. However, the system should be exten- sively tested with mixed hydrolysates. - 6. The composition of the feed to the SCWO reactor S(:W(] cannot be considered a mature technology for destroying agent and energetic hydrolysates. The proposed LMIDS transpiring-wall reactor pro- vides a novel solution to the problem of corrosion and plugging in SCWO reactors. The transpiring-wall SCWO reactor has been tested at bench scale at Sandia National Laboratories in collaboration with GenCorp/ Aerojet and Foster Wheeler. A commercial-scale reac- tor is currently being built for the Army at the Pine Bluff Arsenal by Foster Wheeler/Aerojet to treat smoke and dye wastes with a high salt content (similar in some ways to agent/energetics hydrolysates). This unit is expected to be operational sometime in 1999 but was not operational at the time of this writing. The ~ro O *' ~.. . .. .. .. .. . posect ~;wu unit Is essentially ~crent~ca~ to a unit be- ing constructed for the U.S. Navy for shipboard waste disposal. No extensive testing of the design has been done to date. The committee has the following con- cerns about this technology: 1. The design and manufacture of this unique SCWO reactor may be quite difficult. Fabrication of the transpiring wall may present a significant challenge, both in the choice of materials and in the construction of the platelets. 2. Long-term testing will be necessary to establish that the transpiring-wall reactor will not have . ~ . . . will change with time, either because of a change in the mix of weapons or because of an unsched- uled shutdown of either the agent hydrolysis re- actor or an energetics hydrolysis reactor. It must be established that the SCWO reactor will con- tinue to operate reliably after a sudden change in the composition of the feed stream. 7. The gaseous effluent from the SCWO reactor will be continuously filtered, monitored, and released to the environment. This off-gas will not be passed through a hold-test-and-release process. Continuous monitoring must be demonstrated to ensure that the released off-gas meets safety criteria. Gas Phase Chemical Reduction. The thermal-reduc- tion batch processor/GPCR process has been used com- mercially to treat PCB-contaminated electrical equip- ment. Two full-scale plants have been operating for more than two years in Kwinana in Western Australia, and one plant was operated for a year at a General Motors of Canada facility in St. Catherine's, Ontario. The process will be used here with only minor modifi- cations. Therefore, there is some experience in operat- ing GPCR reactors of the size to be used in the LMIDS. The committee has the following concerns about these units.

OCR for page 102
LOCKHEED MARTIN INTEGRATED DEMILITARIZATION SYSTEM 1. The GPCR reactor must be operated in a closed, contained environment, where fugitive hydrogen emissions can be a serious hazard. Therefore, the design and control of this system must take this danger into account. 2. The monitoring and control system on the GPCR units must ensure that no oxygen or other oxi- dants are present before hydrogen is admitted into the system. The proposed method of separating soot from the gaseous effluent from the GPCR reactor may not be very effective and may result in process reli- ability problems from the accumulation of soot in other parts of the gas-flow path. 4. The GPCR of materials to soot, silica, and a us- able fuel gas must be thoroughly demonstrated. The waste streams may be more complex than anticipated. 5. A method must be developed to ensure that agent (or other hazardous materials) does not condense, adsorb, or accumulate on the internal surfaces of the off-gas hold-test-release tanks. Scale-up. Some aspects of scale-up from demonstra- tion-size equipment should be relatively easy. The SCWO reactors will be the same size as an existing prototype Navy unit. The LMIDS reactors will be de- signed to operate in parallel, and no problem with scale- up is planned. Other aspects of scale-up may be more difficult because not all parts of the process scale in the same way. For example, many mass-transfer processes scale with length, whereas surface and surface wash- out phenomena scale with area; still others, such as the homogeneous hydrolysis reaction, scale with reactor volume. The hydrolysis vessels will have to be care- fully designed to accommodate all three phenomena simultaneously. Overall Technology Package. The technologies se- lected by the technology provider have all been imple- mented with process streams similar to those in the ACWA program. However, they have not been oper- ated as an integrated unit. Furthermore, some of the methods of implementation are new and all but untried at this time (e.g., the transpiring-wall SCWO reactor and the methods for hydrolyzing agent and energetics remaining on metal parts). Thus, although the basic technologies are reasonably mature, certain facets of 113 their implementation and their integration or interfac- ing are still at early stages of development. To prevent severe operating problems, the integrated system must be demonstrated prior to full-scale operation. The full-scale process will have to be designed to be "forgiving," allowing easy visibility and easy mainte- nance of remotely-operated and automated equipment. Robustness Robustness, or the ability to operate with a wide range of feed stocks and operating conditions, appears to be reasonable in all process areas except for the ves- sels used to remove energetics and agents remaining on metal parts. If agent or energetic properties are dif- ferent than anticipated (e.g., more polymerization of the agent than expected), the cleaning method may re- quire significant modifications to achieve the required throughputs. Monitoring and Contro/ The monitoring and control approaches for the pro- cesses in this system are widely used and should be readily implemented. The process materials (with the exception of agents and energetics), temperatures, and pressures in this technology package have all been successfully monitored and controlled in prior applications. App/icabi/ity The technology provider included process design information for rockets and projectiles/mortars and stated that land mines could be easily incorporated as an additional feed stream by adding a disassembly ca- pability for these munitions. Thus, the proposed sys- tem has broad applicability. Process Safety The technology provider proposes using several unique pieces of equipment: a modified (from baseline) rocket-shear machine a rocket hydrolysis vessel for sheared rocket parts, propellant and energetics

OCR for page 102
114 ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS a nose-closure hydrolysis vessel for projectile nose closures a projectile hydrolysis vessel for projectile bodies a burster hydrolysis vessel for projectile bursters energetics destruction reactors agent neutralization reactors a GPCR process that includes a thermal reduction continuous processor for treatment of projectiles and a thermal reduction batch processor for other waste streams transpiring-wall SCWO reactors for destruction of agent and energetic hydrolysates In the LMIDS, the energetics and agent are sepa- rated early in the process, reducing the possibility of an energetically driven release of agent. Most of the hy- drolysis processes operate at low temperatures (90C or 194F) and low pressure (near atmospheric), thus avoiding significant stored energy and reducing pro- cess hazards. The burster hydrolysis vessel is slightly pressurized to achieve temperatures up to 1 35C but does not represent a significant stored-energy hazard. The SCWO reactors operate at 238 aim and 780C and do represent major reservoirs of stored energy. The GPCR processes operate at temperatures up to 850C (1,562F) at low pressure using a hydrogen gas atmo- sphere for destruction of trace amounts of agents and other hazardous materials. Commercial facilities em- ploying this technology are operating (or have oper- ated) in Canada and Australia. However, all of these facilities are located outdoors. To maintain control of potential airborne agent emissions, the GPCR equip- ment for the LMIDS will be located inside a contain- ment or confinement building. Therefore, hydrogen leakage from the GPCR is a safety concern. The team partner responsible for this technology, Eco-Logic, is well aware of this and has commissioned a safety study on this issue (Prugh, 1998~. Recommended safety measures are being considered or have already been implemented. Worker Safety The LMIDS system is basically "forgiving" in that agent and energetic destruction are verified after both of the sequential processes for all ACWs, thus ensur- ing that all agent and energetic material have been destroyed. The separation of energetics from agent and the subsequent destruction of both materials in a 20-percent caustic solution minimizes the risk of ex- plosions. In addition, both processes are operated in structures designed to contain explosive overpressure. Mechanical disassembly processes are derivatives of the baseline processes and are not considered to repre- sent new or increased risk levels for rockets, projec- tiles, or land mines. These processes will be conducted in vessels or structures designed to withstand explo- sive overpressure. The GPCR reactor operates in a hydrogen atmo- sphere and generates methane and other gaseous hy- drocarbons that could burn or explode in the presence of air. Explosion hazards for this process are minimized by purging with inert gas during start-up and shutdown. Considerable industrial experience with high-tempera- ture hydrogen atmospheres has established that these processes can be operated safely. GPCR off-gas could contain small amounts of hydrogen sulfide and hydro- gen chloride, which will be removed in a caustic scrub- ber. Worker exposure to these gases is unlikely. Simi- lar gases in much higher concentrations are routinely handled safely in the petroleum refining and petro- chemical industry. The most significant worker safety issue will prob- ably be maintenance of the hydrolysis vessels in DPE suits. These vessels have conveyor systems that oper- ate in hot caustic solutions. Experience with these sys- tems is limited, and full-scale implementation of this technology, especially during start-up, may require sig- nificant maintenance, thereby increasing the risk of worker exposure to agent. Hydrogen and other combustible gases will be gen- erated in the hydrolysis reactions. Therefore, oxygen must be kept out of the vessel vapor spaces and the associated vapor piping, and these gases must not be allowed to collect in air spaces in the contained process areas. Because these processes operate at very low or negative gauge pressures, the driving force that causes gas leaks into ventilated areas is minimal. The hydroly- sis vessel vapor spaces (which operate under a slight vacuum) are purged with nitrogen gas to prevent un- safe oxygen levels from building up from the in-leak- age of ventilation air. Loss of the nitrogen purge gas would increase the likelihood of an explosion in the vessels or off-gas piping.

OCR for page 102
LOCKHEED MARTIN INTEGRATED DEMILITARIZATION SYSTEM The SCWO reactors and water supply system oper- ate at high pressure and are a source of stored energy. Therefore, it is very important that the reactors be de- signed and maintained in ways that minimize ruptures and leaks. Failures may not result in release to the envi- ronment because of secondary containment, but they could require extensive repair work in DPE suits. Fuze bodies and booster pellets that are not dissolved in the caustic solution also represent an explosive haz- ard in the thermal-reduction batch processor. The tech- nology provider intends to demonstrate a technology that will reduce the size of these parts to ensure their full dissolution. In addition, the thermal-reduction batch processor will be designed to withstand initiation of these components. The primary hazardous materials used in agent and energetic destruction are sodium hydroxide, liquid and gaseous oxygen, hydrogen, and methane. Sodium hy- droxide will be delivered in solid form and dissolved in water to make a 20-percent caustic solution. All of these chemicals are handled routinely and safely in many industries. The technology provider has con- ducted a preliminary hazard analysis and has identified reasonable solutions for events that could create unac- ceptable or undesirable worker safety risks (Lockheed Martin, 1998). Public Safety The likelihood of releases of agent or other regu- lated substances to the atmosphere or to the facility are expected to be extremely small. Hold-test-release svs- tems are applied to all effluent streams except the containment ventilation air and SCWO off-gas. The ventilation system uses tested baseline air cleaning technology. The SCWO off-gas will be cooled con- tinuously, monitored for agent, and passed through a carbon filter before release to the atmosphere. This ap- proach does not meet the hold-test-release criterion for process effluents that has been requested by some stakeholders; but it is not expected to reduce public safety. The primary cause for a release of material contain- ing agent or other regulated substances would be a dis- ruptive explosion. The likelihood of such an event is expected to be extremely small at the conclusion of the design process for the full-scale facility. (This design 115 process is understood to include the completion of a QRA.) A preliminary hazard analysis conducted by the technology provider revealed no events with unaccept- able or undesirable public safety risks. Human Health and the Environment A full evaluation of the impact of the effluents on human health and the environment must await the out- come of health and environmental risk assessments, which cannot be prepared at the current stage of devel- opment for this system. However, some general obser- vations and comments can be made at this time. Process gases leaving the plant will have been treated to remove traces of organic materials (includ- ing agent) and will be monitored or tested to ensure that they do not contain agent or other regulated sub- stances at concentrations above levels established by the EPA for release to the environment. The solid waste streams are 5X metal parts, salt from the SCWO reactors, and carbon residue and silica from the GPCR. All nonmetal solid waste streams are ex- pected to be suitable for release to a hazardous-waste landfill. The 5X metal parts are expected to be suitable for reuse as scrap for metallurgical processes. Effluent Characterization, Management, and Impact on Human Health and the Environment Gas Streams. These streams originate in the SCWO reactors, the ventilation air exhaust from contained pro- cess areas, and exhaust gases from the steam boiler (fu- eled partly by the GPCR reactor) and the hydrogen gen- erator. Experience indicates that the gas streams will be free of agent and other regulated substances. Dem- onstration tests would provide reassurance that the de- sign works as planned for the treatment of process gas and that all regulated substances in the effluent gases are identified and measured. The gas streams from the SCWO reactors and the ventilation air exhaust from contained process areas are monitored, passed through activated-carbon filters, and released to the environment. (The exhaust gas from the SCWO reactors has been shown to consist principally of carbon dioxide and water vapor with trace amounts of low molecular weight hydrocarbons.) The inlet to the SCWO reactor will also be monitored, and detection

OCR for page 102
116 ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS of unacceptable levels of hazardous materials will trig- ger an emergency response, including isolation and shutdown. The exhaust gases from the steam boiler and hydrogen generator will not be monitored. The compo- sition of these gas streams should be characterized dur- ing demonstrations of the LMIDS. Acid gases from the GPCR process will be absorbed in a caustic scrubber, and the effluent gas will be passed through a hold-test-release procedure. If shown to have acceptably low concentrations of regulated substances and to be essentially agent free, the gas will be used as fuel in the LMIDS steam boilers. Permits will be re- quired to use this gas stream as boiler fuel based on full characterization of the GPCR process off-gas streams during demonstration. Metal Parts. These parts will be treated in the GPCR process and will not be released until they have been treated to the 5X standard. As long as the treatment procedure is monitored, the metal parts should need no further testing and can be released. The cleaned parts are not expected to pose any threat to human health or the environment. Salts. Salts from the SCWO reactors will contain the sodium salts of fluoride, chloride, sulfate, phosphate, nitrate, and nitrite and are expected to contain trace amounts of low molecular weight hydrocarbons. The committee expects that this stream will be classified as hazardous, although this has not yet been determined by testing. The salts will be verified to be agent free before they are released for off-site stabilization and placement in a hazardous-waste landfill. Stabilization of salt wastes is very difficult. The leaching levels of hazardous constituents in the salt will have to be inves- tigated to determine if additives will be necessary to ensure stabilization and whether a formula for a stabi- lized mixture can be developed. If stabilization and burial in a hazardous-waste landfill are feasible, they would provide adequate protection to human health and the environment. Demonstration tests are necessary to characterize fully the composition of the salts to identify all regulated substances and determine their concentrations. Dunnage Material. This material is subjected to silica and will be sent off site for stabilization and dis- posal in a hazardous-waste landfill. Demonstration tests will have to characterize fully the composition of the solids to identify all regulated substances and their concentrations. Resource Requirements The chemicals required for processing are sodium hydroxide, liquid oxygen, liquid nitrogen, and kero- sene (or isopropyl alcohol). The level of usage is not considered to represent an unusual demand on avail- able industrial sources. The utilities required for opera- tion and maintenance are electricity, water, and gas. The amounts required are similar to the amounts for the Army's baseline facilities except for the larger con- sumption of methane for the production of steam and hydrogen. Manpower required for operation and main- tenance will probably be similar to the manpower for the Army's baseline facilities, assuming that mainte- nance concerns expressed earlier are addressed as the design progresses. Environmenta/ Compliance and Permitting Compliance with environmental regulations will re- quire careful, detailed design of the plant, as well as careful operation and environmental management. There are no inherent reasons why the combination of technologies in the LMIDS technology package should lead to unusual problems. The absence of liquid emis- sions is an important advantage of the process. The same is true for permitting. All process waste streams except the SCWO off-gas will be evaluated prior to release to confirm that regulated substances are absent or at acceptably low concentrations. The SCWO off-gas will be scrubbed, monitored, and passed through activated carbon filters. One aspect of the process that may lead to permit- ting problems is the use of the cleaned GPCR off-gas as a boiler fuel. Extensive testing may be required to char- acterize this stream to ensure that it can be used safely. STEPS REQUIRED FOR IMPLEMENTATION n~gn-temperature hydrogen recluct~on In the (~K pro-Overall, the LMIDS appears to be capable of operat cess. The solid process effluent is carbon residue anding as proposed by the technology provider, but the

OCR for page 102
LOCKHEED MARTIN INTEGRATED DEMILITARIZATION SYSTEM process must be developed further, especially the inter- faces between and integration of the nroceL~Ls unites. If . . ~ ~ ~ ~ the civ~ were to proceed towards full-scale imple- mentation, the next step should be to design, build, and operate a pilot-scale system that incorporates all of the unit operations into a fully functional, integrated pro- cess. Full-scale implementation will involve interfac- ing and integrating batch processes (the hydrolysis re- actors and the thermal reduction batch processor) with continuous processes (the SCWO reactor, the thermal reduction continuous processor, and the GPCR reac- tor). These interfaces must be tested at the demonstra- tion stage to avoid implementation problems. Also, all problems with materials of construction and waste characterization will have to be solved before imple- mentation. However, no problems have been identified that would prevent eventual full-scale implementation. In addition to demonstrating that the overall process is capable of long-term operation, specific objectives for three of the pilot-scale unit operations are described below. Pi/ot-Sca/e Eva/uation for Hydro/ysis of Energetics 1. Establish that the mechanical equipment used in the energetics hydrolysis vessels can tolerate the harsh conditions without excess maintenance. 2. Determine whether the hydrolysis of aluminum . . . . . . - . together with energet~cs presents any problems. Pi/ot-Sca/e Eva/uation for SCWO 1. Show that the SCWO reactor platelet wall can be constructed. 2. Demonstrate that the SCWO reactor can be oper- ated for sufficient periods of time without exces . . . . slve clogging or corrosion. 3. Fully characterize the SCWO gaseous effluent from mixed hydrolysates of agent and energetics. A-. Establish that the continuous monitoring of the SCWO gaseous effluent ensures against unac- ceptable releases of hazardous materials. Pi/ot-Sca/e Eva/uation for GPCR 117 2. Ascertain whether the large quantity of soot gen- erated in the thermal-reduction batch process will create any problems. FINDINGS Finding LM-1. The disassembly methods proposed in the LMIDS are based largely on the baseline disassem- bly methods. The proposed modifications appear to be reasonable, but testing will be necessary to verify that performance, reliability, and production objectives can be met. Finding LM-2. Primary agent decomposition and detoxification is achieved using a strong caustic hy- drolysis of bulk agent a proven technology. Overall, the implementation of agent hydrolysis in the LMIDS is sound. Finding LM-3. Primary decomposition and deactiva- tion of energetics is also achieved using a strong caus- tic hydrolysis. This technology has been tested but is less mature than agent hydrolysis. The implementation of this technology in the LMIDS is reasonable but will require thorough testing at the pilot scale. Finding LM-4. The method of removing agent from metal parts caustic solution jet wash-out followed by the movement of the parts in baskets through a caustic bath is new and unproven. It is expected that this method can be made to work, but the effort and time required to come to acceptable performance goals may be longer than anticipated and may require alternate methods. Thus, it will be desirable to have alternate plans if the desired detoxification efficiencies are not achieved (e.g., increase the capacity of the GPCR unit to allow for more than the planned agent cleanup load). finding LM-5. the hot-caustic environments in the initial hydrolysis vessels will pose severe challenges to the reliability and operability of the equipment . . .. . - r - ~ ~ - - --- - - -l -- -r -- ~ns~de these vessels, especially the basket transport mechanisms. Finding LM-6. The SCWO process appears to be ca- pable of completing the destruction of both agent and energetics in the hYdrolYsates. The keY area of uncer- tainty in the technology prov~cler s proposed application , , , .. ~. .. .. 1. Fully characterize the GPCR gaseous effluent and , a, l l l l l establish whether it can be used as a boiler fuel. of SCWO is the use of its proprietary transpiring-wall

OCR for page 102
118 ALTERNATIVE TECHNOLOGIES FOR DEMILITARIZATION OF ASSEMBLED CHEMICAL WEAPONS tubular reactor. The demonstration of this technology will be essential to proving the efficacy of this crucial step in the agent/energetics destruction process. monitored, and passed through activated carbon. This treatment appears to be appropriate for the anticipated composition of the SCWO off-gases. Finding LM-7. The crystallization and evaporation operations have not been tested for this application. These conventional technologies, which are expected to work effectively, must still be tested. Finding LM-X. The use of GPCR in an enclosed envi- ronment raises unique safety concerns because of the presence of hot hydrogen gas. Hydrogen is handled routinely (and safely) in the chemical industry, and the technology provider is aware of the hazards. Imple- mentation of this technology will require a design that ensures that these hazards are thoroughly understood and mitigated. Finding LM-9. The gas stream from SCWO is not sub- jected to hold-test-release. Instead, the gas is scrubbed, finding LM-l(). Lot-scale testing will be necessary to refine the component technologies and demonstrate that these technologies can be operated as an integrated system. Finding LM-ll. The proposed use of the cleaned GPCR off-gas as a boiler fuel poses unique permitting challenges. Any demonstration must characterize this stream to ensure that permitting as a boiler fuel is pos sible. If this off-gas cannot be used as a boiler fuel, significant process modifications may be necessary. Finding LM-12. All of the findings in the NRC report, Using Supercritical Water to Treat Hydrolysate from V7( Neutralization (NRC, 1998), apply to the LMIDS SCWO system (see Appendix F).