5

Update of General Findings and Recommendations

Chapter 11 of the committee’s initial report, Review and Evaluation of Alternative Technologies for Demilitarization of Assembled Chemical Weapons, included 16 general findings and seven general recommendations (NRC, 1999). For the most part, these findings and recommendations remain unaffected by the results of the demonstration tests of the three technology packages. Each of these findings and recommendations is quoted below followed by a discussion of the effect of the demonstration tests results. New findings are then presented.

REVIEW OF EARLIER FINDINGS AND RECOMMENDATIONS

General Finding 1. The chemistries of all four of the primary technologies, (hydrolysis, SILVER II, plasma arc, and SET) as proposed, can decompose the chemical agents with destruction efficiencies of 99.9999 percent. However, each technology package raises other technical issues that must be resolved. One of the crucial issues is the identity and disposition of by-products.

Two of the three technology packages chosen for ACWA demonstration rely on hydrolysis as the primary treatment process. The third is based on plasma arc technology. Hydrolysis of agents was not a direct part of the demonstrations. However, the PMACWA produced approximately 1,100 gallons of GB hydrolysate, 400 gallons of VX hydrolysate, and 4,200 gallons of HD hydrolysate as starting materials for the demonstrations. The Army’s ability to produce agent hydrolysates that show no agent above detection limits confirms the effectiveness of hydrolysis in destroying both mustard and nerve agents to a DRE of 99.9999 percent.

Although the Burns and Roe team did not conduct demonstration tests for the destruction of neat chemical agents, the committee continues to believe that a properly engineered plasma arc device could destroy both mustard and nerve agents to a DRE of 99.9999 percent.

General Finding 2. The technology base for the hydrolysis of energetic materials is not as mature as it is for chemical agents. Chemical methods of destroying energetics have only been considered recently. Therefore, there has been relatively little experience with the alkaline decomposition of ACWA-specific energetic materials (compared to experience with chemical agents). The following significant issues should be resolved to reduce uncertainties about the effectiveness and safety of using hydrolysis operations for destroying energetic materials:

  • the particle size reduction of energetics that must be achieved for proper operation

  • the solubility of energetics in specific alkaline solutions

  • process design of the unit operation and the identification of processing parameters (such as the degree of agitation and reactor residence time) necessary for complete hydrolysis

  • the characterization of actual products and by-products of hydrolysis as a function of the extent of reaction

  • the selection of chemical sensors and process control strategies to ensure that the unit operation following hydrolysis can accept the products of hydrolysis

  • development of a preventative maintenance program that minimizes the possibility of incidents during the cleanup of accumulated precipitates

General Finding 3. The conditions under which aromatic nitro compounds, such as trinitrotoluene (TNT) or picric acid, will emulsify in the aqueous phase and not be completely hydrolyzed are not well understood. Therefore, this type of material could be present in the output stream from an energetic hydrolysis step.

General Finding 4. The products of hydrolysis of some energetic materials have not been characterized well enough to support simultaneous hydrolysis of different kinds of energetic materials in the same batch reactor.

General Recommendation 5. Whatever unit operation immediately follows the hydrolysis of energetic materials should be designed to accept emulsified aromatic



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 26
Evaluation of Demonstration Test Results of Alternative Technologies for Demilitarization of Assembled Chemical Weapons: A Supplemental Review 5 Update of General Findings and Recommendations Chapter 11 of the committee’s initial report, Review and Evaluation of Alternative Technologies for Demilitarization of Assembled Chemical Weapons, included 16 general findings and seven general recommendations (NRC, 1999). For the most part, these findings and recommendations remain unaffected by the results of the demonstration tests of the three technology packages. Each of these findings and recommendations is quoted below followed by a discussion of the effect of the demonstration tests results. New findings are then presented. REVIEW OF EARLIER FINDINGS AND RECOMMENDATIONS General Finding 1. The chemistries of all four of the primary technologies, (hydrolysis, SILVER II, plasma arc, and SET) as proposed, can decompose the chemical agents with destruction efficiencies of 99.9999 percent. However, each technology package raises other technical issues that must be resolved. One of the crucial issues is the identity and disposition of by-products. Two of the three technology packages chosen for ACWA demonstration rely on hydrolysis as the primary treatment process. The third is based on plasma arc technology. Hydrolysis of agents was not a direct part of the demonstrations. However, the PMACWA produced approximately 1,100 gallons of GB hydrolysate, 400 gallons of VX hydrolysate, and 4,200 gallons of HD hydrolysate as starting materials for the demonstrations. The Army’s ability to produce agent hydrolysates that show no agent above detection limits confirms the effectiveness of hydrolysis in destroying both mustard and nerve agents to a DRE of 99.9999 percent. Although the Burns and Roe team did not conduct demonstration tests for the destruction of neat chemical agents, the committee continues to believe that a properly engineered plasma arc device could destroy both mustard and nerve agents to a DRE of 99.9999 percent. General Finding 2. The technology base for the hydrolysis of energetic materials is not as mature as it is for chemical agents. Chemical methods of destroying energetics have only been considered recently. Therefore, there has been relatively little experience with the alkaline decomposition of ACWA-specific energetic materials (compared to experience with chemical agents). The following significant issues should be resolved to reduce uncertainties about the effectiveness and safety of using hydrolysis operations for destroying energetic materials: the particle size reduction of energetics that must be achieved for proper operation the solubility of energetics in specific alkaline solutions process design of the unit operation and the identification of processing parameters (such as the degree of agitation and reactor residence time) necessary for complete hydrolysis the characterization of actual products and by-products of hydrolysis as a function of the extent of reaction the selection of chemical sensors and process control strategies to ensure that the unit operation following hydrolysis can accept the products of hydrolysis development of a preventative maintenance program that minimizes the possibility of incidents during the cleanup of accumulated precipitates General Finding 3. The conditions under which aromatic nitro compounds, such as trinitrotoluene (TNT) or picric acid, will emulsify in the aqueous phase and not be completely hydrolyzed are not well understood. Therefore, this type of material could be present in the output stream from an energetic hydrolysis step. General Finding 4. The products of hydrolysis of some energetic materials have not been characterized well enough to support simultaneous hydrolysis of different kinds of energetic materials in the same batch reactor. General Recommendation 5. Whatever unit operation immediately follows the hydrolysis of energetic materials should be designed to accept emulsified aromatic

OCR for page 26
Evaluation of Demonstration Test Results of Alternative Technologies for Demilitarization of Assembled Chemical Weapons: A Supplemental Review nitro compounds, such as TNT or picric acid, as contaminants in the aqueous feed stream. (See General Finding 3.) General Recommendation 6. Simultaneous processing of different types of energetic materials should not be performed until there is substantial evidence that the intermediates formed from the hydrolysis of aromatic nitro compounds will not combine with M28 propellant additives or ordnance fuze components to form extremely sensitive explosives, such as lead picrate. (See General Finding 4.) The hydrolysis of energetics performed during the ACWA demonstrations substantiates the findings and recommendations cited above. The committee is concerned that the technology for the hydrolysis of energetic materials may be even more immature than was originally anticipated. Problems were experienced in scale-up test runs for Comp B and tetrytol that were not apparent during laboratory-scale tests. Because the hydrolysis of lead stearate produces lead hydroxide, toxicity is a potential problem, justifying the committee’s concern about the possible formation of lead picrate if M28 propellant is simultaneously hydrolyzed with Comp B or tetrytol bursters. The Army and General Atomics have acknowledged that more work needs to be done before the hydrolysis of energetics can be considered safe and effective at production-scale levels (DOD, 1999c, 1999d; General Atomics, 1999a). The demonstration tests provided a large body of data. The Army has assembled a team of agencies to analyze the preliminary results, assess the efficacy of the processes, and identify problems and their causes and effects. Further experimentation is also being planned. General Finding 5. The primary chemical decomposition process in all of the technology packages produces environmentally unacceptable reaction products. Therefore, all of the packages are complicated processes that include subsequent treatment step(s) to modify these products. The General Atomics and the Parsons-AlliedSignal technology packages use hydrolysis for primary chemical decomposition, whereas the primary treatment process in the Burns and Roe package is the PWC. Analyses of the agent hydrolysates produced by the PMACWA for the demonstration tests confirmed General Finding 5. In other words, the hydrolysates contained Schedule 2 compounds and other products that are not suitable for direct discharge to the environment. The PWC used for the demonstration was not tested on agents or under conditions that produced acceptable synfuel. Consequently, PWC by-products produced from agents must still be characterized. General Finding 6. The waste streams of all of the ACWA technology packages could contain very small amounts of hazardous substances (besides any residual chemical agent). These substances were not fully characterized at the time of this report; therefore, all waste streams must be characterized to ensure that human health and the environment are protected. If more than one phase (gas, liquid, or solid) is present in a waste stream, each phase should be characterized separately. Although a large body of data was gathered, the tests of unit operations from the three technology packages during the demonstrations were of short duration and were conducted with undersized reactors. In addition, the operating conditions were not optimized. Thus, the effluents that were produced may not be completely representative of the effluents that would be produced in units operating at different conditions (e.g., temperature, pressure, etc.). General Finding 7. None of the proposed technology packages complies completely with the hold-test-release concept for all gaseous effluents (both process and ventilation effluents). General Finding 8. Hold-test-release of gaseous effluents may not ensure against a release of agent or other hazardous material to the atmosphere. No evidence shows that hold-test-release provides a higher level of safety than current continuous monitoring methods for gaseous streams with low levels of contamination. Furthermore, none of the technologies provides for hold-test-release of effluents from ventilation systems that handle large volumes of gases from contaminated process areas. Because the basic configurations of the three demonstrated technology packages have not changed, General Findings 7 and 8 remain unchanged. Hold-test-release was not included in the demonstration tests. General Finding 9. Solid salts will be hazardous waste, either because they are derived from hazardous waste...or because they leach heavy metals above the levels allowed by the Resource Conservation and Recovery Act Toxicity Characteristic Leaching Procedure. Stabilization— mixing waste with a reagent or reagents to reduce the leachability of heavy metals —will probably be required before the salts can be sent to a landfill. The potentially high chloride and nitrate content of these salts will make the waste difficult to stabilize, and treatability studies will be necessary to determine a proper stabilization formula. General Finding 9 remains unchanged because the demonstrations did not test the ability of unit operations to produce dried salts. General Finding 10. Testing, verification, and integration beyond the 1999 demonstration phase will be necessary because the scale-up of a process can present many unexpected challenges, and the ACWA demonstrations were limited in nature. The committee considers the demonstration tests as “proof-of-concept” tests of the demonstrated unit operations. In nearly all cases, the conditions during the tests had to be modified in some respects, and, in many cases, significant alterations had to be made to the procedures. Finally, the critical step of integrating the unit operations has not yet been addressed by the technology providers for any of the demonstrated technology packages.

OCR for page 26
Evaluation of Demonstration Test Results of Alternative Technologies for Demilitarization of Assembled Chemical Weapons: A Supplemental Review The committee believes that the following general findings and recommendations from the committee’s original report were not affected in any way by the demonstration tests of the three technology packages. General Finding 11. Although a comprehensive quantitative risk assessment (QRA), health risk assessment (HRA), and ecological risk assessment (similar to assessments performed for the baseline process) cannot be completed at this stage of process development, these assessments will have to be performed and refined as process development continues. General Finding 12. The “optimum” system for a particular chemical weapons storage depot might include a combination of unit operations from the technology packages considered in this report. General Finding 13. Some of the ACWA technology providers propose that some effluent streams be used commercially. New or modified regulations may have to be developed to determine if these effluent streams can be recovered or reused. General Finding 14. An extraordinary commitment of resources will be necessary to complete the destruction of the assembled chemical weapons stockpile in time to meet the current deadline using any of the ACWA technology packages. This would demand a concerted national effort. It is unlikely that any of the technology packages could meet this deadline. General Finding 15. The Dialogue process for identifying an alternative technology is likely to reduce the level of public opposition to that technology. The committee believes that the Dialogue has been and continues to be a positive force for public acceptance of alternatives to incineration. Although the Dialogue process requires a significant commitment of time and resources, it has been a critical component of the ACWA program to date. General Finding 16. Although the committee did not have access to scientific data on the attributes of a technology that would be most acceptable to the public, input from members of the active publics and previous research indicates that technologies with the following characteristics are likely to stimulate less public opposition: minimal emissions, particularly gaseous continuous monitoring of effluents to verify that the process is operating as designed (process assurance measurement) provisions for representatives of the local community to observe and participate in the process assurance measurement General Recommendation 1. If a decision is made to move forward with any of the ACWA technology packages, substantial additional testing, verification, and integration should be performed prior to full-scale implementation (see General Finding 10). General Recommendation 2. The sampling and analysis programs at each phase of development should be carefully reviewed to ensure that the characterization of trace components is as comprehensive as possible to avoid surprises in the implementation of the selected technology (see General Finding 6). General Recommendation 3. If a decision is made to move forward with any of these technology packages, health and safety evaluations should progress from qualitative assessments to more quantitative assessments as the process design matures. Quantitative (QRA), health (HRA), and ecological risk assessments should be conducted as soon as is practical. Early initiation of these assessments will allow findings to be implemented with minimal cost and schedule impact (see General Finding 11). General Recommendation 4. Any of these technology packages, or any component of these technology packages, should be selected on a site-specific basis (General Finding 12). General Recommendation 7. The Department of Defense should continue to support the Dialogue throughout the current ACWA program and should seriously consider the participation of the Dialogue in follow-on programs. SUPPLEMENTAL GENERAL FINDINGS In the Statement of Task for this report, the committee was asked to determine if any of the technology packages chosen for demonstrations was “viable to proceed with implementation of a pilot-scale program that would employ any of these technologies.” The committee has evaluated the maturity of each unit operation in the proceeding chapters of this report. Table 5-1 provides a summary of the committee’s assessments. General Finding 1. Based on the committee’s assessment of the maturity of the various unit operations (as summarized in Table 5-1 ), none of the three technology packages is ready for integrated pilot programming, although certain unit operations are sufficiently mature to bypass pilot testing (e.g., hydrolysis of agent). The demonstrated PWC system of the Burns and Roe technology package does not appear to be ready for pilot testing for any assembled chemical weapons materials. The demonstrated components of the General Atomics technology package are close to achieving an overall acceptable level of maturity. However, certain key demonstration tests were not performed or the results were inconclusive. The demonstrated components of the Parsons-AlliedSignal technology package are also close

OCR for page 26
Evaluation of Demonstration Test Results of Alternative Technologies for Demilitarization of Assembled Chemical Weapons: A Supplemental Review TABLE 5-1 Summary Evaluation of the Maturity of Demonstrated Unit Operations and Processesa   Hydrolysates Agent Munitions   Unit Operation/Process VX/GB HD Energetics VX/GB HD Energetics Other Burns and Roe               Plasma waste converterb C C D D D E Cc, d, e General Atomics               Hydrolysis       A A     Rotary hydrolyzer           C   Shredding/hydropulping             Ac SCWO B B C       Cc Parsons-AlliedSignal               Munitions accessing       B B B   Hydrolysis       A A C   Biotreatment D A A         Catalytic oxidation             Be Metal parts treater       B B D Bd Note: Environmental and safety issues were considered in assigning maturity categorizations. Schedule and cost issues were not considered. a The letter designations are defined as follows (a blank space indicates categorization was not applicable for that material). A Demonstration provides sufficient information to allow moving forward to full-scale design with reasonable probability of success. B Demonstration provides sufficient information to allow moving forward to the pilot stage with reasonable probability of success. C Demonstration indicates that unit operation or process requires additional refinement and additional demonstration before moving forward to pilot stage. D Not demonstrated; more R&D required. E Demonstrated unit operation or process is inappropriate for treatment. b Includes integrated gas polishing system to support demonstration c Dunnage d Metal parts e Effluents to being ready for pilot testing, but only for mustard-bearing munitions. Hydrolysis of agent (used in the General Atomics and Parsons-AlliedSignal technology packages) appears sufficiently mature to consider full scale application to any assembled chemical weapons. Similarly, biotreatment of hydrolysate (Parsons-AlliedSignal technology package) appears sufficiently mature for full scale application to mustard munitions. General Finding 2. The demonstration tests were not operated long enough to demonstrate reliability and long-term operation. The PMACWA’s demonstration plan was severely constrained by both scheduling deadlines and available budget resources. The technology providers did not have enough time for systemization (preoperational testing). Consequently, the committee maintains that these tests were simply “proof-of-concept” demonstrations that indicate whether or not a particular unit operation (with more development) might be applicable to the disposal of assembled chemical munitions. General Finding 3. The committee reiterates that none of the unit operations has yet been integrated into a complete system. The lack of integration is a major concern and a significant obstacle to full-scale implementation.