The Kentucky Revised Statutes (KRS) 224.50-130 state that the Kentucky Energy and Environment Cabinet shall consider certain criteria in making a decision to issue a permit to any facility for the treatment or disposal of chemical agents. These criteria include whether the technology has been fully proven or demonstrated as effective to provide assurance of destruction or neutralization at an efficiency of 99.9999 percent (also known as “six-nines” destruction) for each compound to be treated. This statutory requirement is also reflected in the Kentucky Administrative Regulations (KAR) 401 KAR 34:350, where any proposed treatment or destruction technology for the treatment of nerve (i.e., GB and VX) and blister (i.e. mustard) agents must be proven in an operational facility of scale, configuration, and throughput comparable to the proposed facility for a period of time sufficient to provide assurance of 99.9999 percent destruction or neutralization (i.e., destruction efficiency, or DE) of each substance as determined by the following equation:
= Mass feed rate of waste to the incinerator,
= Mass emission rate of the same waste present in exhaust emissions prior to release to the atmosphere, and
= Mass removal rate of waste via the incinerator residues.
This approach for assessing DE is directly applicable to the operation of an incinerator, where any surviving agent would necessarily reside in either the exhaust gases or in the solid residue. The Blue Grass Chemical Agent Destruction Pilot Plant (BGCAPP) will initially operate under the Resource Conservation and Recovery Act (RCRA) Research, Development and Demonstration (RD&D) permit EPA ID KY8-213-820-105, issued by the Kentucky Department for Environmental Protection (KDEP) to Blue Grass Army Depot (BGAD), BGCAPP, and Bechtel Parsons Blue Grass on September 30, 2005. Recognizing that BGCAPP is a neutralization facility, the KDEP modified the KAR DE calculation such that the current RD&D permit states that BGCAPP shall demonstrate 99.9999 percent DE on the initial batch of each chemical agent to be treated. According to RD&D Permit Condition T-9, DE is to be calculated as follows:
= Mass of agent per batch entering into the agent neutralization system (ANS) reactor, and
= Mass of agent per batch exiting the ANS reactor in the hydrolysate.
The current RD&D Permit, Appendix B Compliance Schedule, requires BGCAPP, at least 6 months before receiving waste, to submit to the Hazardous Waste Branch Manager, the agent neutralization reactor (ANR) DE Test Plan for the 99.9999 percent DE in the ANR (Paragraph 19), as well as a Waste Analysis Plan defining all target release levels as defined in the RD&D application and other areas yet to be determined (Paragraph 21). Although BGCAPP presented its original DE approach to the committee, it recognized that the deletion of the washout functions may impact this approach and presented two other options it is considering for the calculation of DE that could accommodate the change in the process flow pathways.
The equation for DE in the RD&D permit is a modified version of that found in the KAR and assumes that almost all agent would pass through and be treated in the ANS. However, a rigorous consideration of the process flow pathways shows that it was conceivable that agent could also be present as vapor generated by the draining and washout operations, and released into the processing room air, and from the ANS headspaces. Furthermore, agent adhering to drained projectiles would be transported to the metals parts treatment unit (MPT), and if any agent survived treatment there, it would then go on to the off-gas treatment system (OTM). However, with munitions washout, the reasonable expectation was that the quantity of agent in these alternative streams would be negligible with regard to calculating DE, and that almost all agent would pass through the ANS. Therefore, DE could be assessed merely by measuring the quantity of agent in the ANS after processing (M2).
Individual projectiles will be weighed after draining to measure the completeness of the drain. This provides a reasonable estimate for the amount of agent transferred to the agent storage tank, which would then guide the quantity of caustic to be added to achieve the correct ratio for ensuring hydrolysis of the agent. Once the agent and caustic are combined, the de facto BGCAPP implementation of the RD&D permit to calculate DE would use agent concentrations in the feed and effluent streams; that is,
= Concentration of agent per batch entering into the ANS reactor, and
= Concentration of agent per batch exiting the ANS reactor in the hydrolysate.
This approach greatly simplifies the calculation of the DE and the supporting analytical measurements. It was assumed that the concentration of GB in caustic entering the ANR would be 7.5 wt% agent, in accordance with the operating design specifications. This is equivalent to a fractional concentration of 0.075, the value for C1 of Equation 3. Six-nines destruction requires that the concentration be reduced by a fraction equivalent to (0.999999) × (0.075) = 0.074999925, which means that maximum allowable residual concentration would be (0.075) − (0.074999925) = 0.000000075. This value, more commonly expressed as 75 parts per billion (ppb), is the maximum allowable concentration in the ANS before exiting as hydrolysate effluent (stream #451, the C2 value of the Equation 3). Analytical measurement to ascertain destruction to this level was based on measuring a concentration of 75 ppb or less.
This concentration-based DE assumes that the volume entering the ANS would be equivalent to the volume exiting. However, the concentration-based DE approach will be difficult or impossible to implement because, after washout deletion, the agent will now be partitioned between multiple processing pathways.
The committee recognizes that the following discussion is complex in places. This is the nature of the system being discussed. The reader is directed to Figure 3-1 for help in following the discussion. Under the current permit, the expectation is that all but a trace of agent will pass through the ANS, which includes the ANR. The DE would be calculated, as described above, by assuming a GB recipe of 7.5 wt% agent in caustic entering the ANR and would require an analytical clearance of less than 75 ppb in the exiting hydrolysate effluent to demonstrate 99.9999 percent destruction. The current permit does not address VX treatment. The VX treatment campaign will be conducted under a RCRA Part B permit that is currently being prepared for submission to KDEP. However, under the current plant configuration, the expectation is that the DE would be calculated by assuming a VX recipe of 16.6 wt% agent in caustic entering the ANR with an analytical clearance of less than 166 ppb in the hydrolysate effluent to demonstrate 99.9999 percent destruction. The comparison of the percentage concentration of the agent(s) in the ANR with the fractional concentrations in the hydrolysate for ascertaining DE is referred to by BGCAPP as DE calculation Approach 1.1
Upon washout deletion, however, a greater amount of residual agent will now be treated within the energetics batch hydrolyzers (EBHs), the energetics neutralization system (ENS), and the MPT. Therefore, the DE calculation established in the current RD&D permit would no longer account for all agent treatment effluent or residue. Under the new configuration, agent would be distributed among multiple solid, liquid, and vapor process streams. The mass of agent entering the ANS, EBHs, and MPT will not be known and will vary on a batch-to-batch basis. In addition, it is not certain that the proposed agent recipe for the ANS would be applicable to agent destruction in the ENS to affect an agent concentration in the neutralized energetics hydrolysate less than the assumed clearance concentrations of 75 (or 166) ppb in Approach 1. Consequently, the assumed clearance concentrations presented by BGCAPP technical staff are now less valid than before and cannot be used for calculating a DE value that would be in accord with the KRS, the KAR or the RD&D permit. Therefore, it will be necessary to modify
1 John McArthur, environmental manager, Bechtel Parsons Blue Grass (BPBG), “Destruction Efficiency Considerations,” presentation to the committee on September 9, 2015.
the existing permit to establish an alternate DE calculation methodology, staying within the statutory and regulatory DE requirements for 99.9999 percent destruction or neutralization as shown in the Equation 1.
The partitioning of agent across additional streams also introduces the need to conduct more monitoring than in the original DE approach. The agent concentrations in some of these streams could be quite low. This could pose a challenge in identifying monitoring technologies or strategies of sufficient sensitivity to measure these concentrations, be they new technologies introduced into BGCAPP or the adaptation of existing BGCAPP monitoring technologies. Additionally, the validation and acceptance of new monitoring technologies or strategies takes time and could have a schedule impact on BGCAPP operations. This committee is not in the position to identify the magnitude of these challenges and recommend solutions, but believes this is a potentially significant issue that BGCAPP management needs to be aware of.
Finding 3-1. With washout deletion, the current methodology for calculating whether BGCAPP meets the statutory and regulatory requirement for a DE of 99.9999 percent will no longer be applicable. This is because the drained and washed out agent will no longer go only to the ANS. Instead, a greater amount of residual agent remaining in the rocket warhead pieces will now be processed in the EBHs and the ENS, and residual agent in the projectiles and possibly on rocket warhead pieces will now be processed through the MPT.
Finding 3-2. The partitioning of agent across additional process streams will introduce monitoring challenges that BGCAPP needs to be aware of. It may be difficult to identify monitoring technologies or strategies of sufficient sensitivity to measure what are expected to be low concentrations of agent in some streams. Additionally, the identification of new technologies or strategies carries the risk of a negative impact on the BGCAPP schedule.
The original approach to be used in the DE calculations will no longer be applicable after washout deletion. Without the water washout, more agent will remain in the projectile bodies and rocket warheads, and any new DE determination will need to address issues raised with the new configuration. More agent from projectiles exiting the projectile handling system (PHS) will be partitioned between the ANS and the MPT, and more agent from rocket warheads will be parti-
tioned between the ANS and the EBH/ENS. Furthermore, the fractions of agent that will be partitioned into the MPT or into the EBH/ENS will vary depending on the percentage of undrained agent remaining in each munition. Because the MPT, EBH, and ENS units are operated at high temperature and the energetics hydrolysis systems use a high concentration of sodium hydroxide, it may be that the agent partitioned into these units will be completely destroyed. However, the efficiency of these units for destroying agent present at the higher loadings after washout deletion is not known. For example, the EBHs were designed to neutralize energetics, and it is possible that a fraction of the agent may survive the EBHs.2 Therefore, the effluents from the EBH/ENS must be considered as part of the overall DE calculation.
There is a possibility that agent will be present in the effluents from the EBHs. Any such agent will need to be considered as part of the overall DE calculation. Prior experience with the caustic hydrolysis of GB and VX suggests that the agents will be completely destroyed by caustic present in the EBHs. This expectation is consistent with calculations by BGCAPP that predict that there will be sufficient excess caustic to ensure quantitative destruction, and with the fact that GB is soluble in the caustic solution. However, VX is not soluble in the caustic solution and is highly surface adsorptive. Hence, it has a better chance of surviving as a result of either incomplete mixing or sequestration in crevices and pores in the metal parts. Further, there is also a chance that a fraction of the agent, particularly GB, which has a lower boiling point than VX, will be partitioned into the EBH off-gas treatment system (OTE). These considerations support the conclusion that agent partitioning into the EBH and ENR effluents must be accounted for in the DE calculation, which will consequently be complicated by the fact that there are three effluent streams that must be accounted for. These are considered in turn in the following text.
Undissolved metal parts will be removed from the bottom of the EBHs and transferred to the MPT. Based on previous experience in the chemical demilitarization program and process modeling, the high temperature and long residence time in the MPT is expected to destroy any agent remaining on the metal parts.3 Therefore, agent on metal parts from the EBHs processed in the MPT is not expected to affect calculation of the DE; that is, measurement of process stream #7652 for agent would not be required.4 However, the MPT was not initially intended for treating larger quantities of agent, as will be the case with the deletion of washout, and there is a possibility that volatilized agent could enter the OTM. Due to the change of circumstances, it would be necessary to show that additional agent loading to the MPT would not affect the calculation of DE through either calculation or demonstration; this is considered in more detail below.
Finding 3-3. It is likely that the combination of the EBH and MPT treatment conditions will be sufficient to destroy all residual agent residing on rocket warhead pieces. This, however, needs to be shown through either calculations or demonstration.
Recommendation 3-1. BGCAPP should calculate or otherwise demonstrate a 99.9999 percent (“six-nines”) destruction efficiency (DE) for residual agent residing on rocket warhead pieces exiting the metals parts treatment unit (MPT). This would provide assurance that the solid effluent from the MPT (stream #7652) generated during rocket campaigns is free of agent to ensure compliance with DE requirements.
The second effluent stream from the EBHs is liquid hydrolysate, which will be transferred to the ENS, where the hydrolysate will be further treated with caustic but at higher temperature and pressure (300°F and 3.1 atm). The ENS generates a liquid effluent stream that is transferred outside the agent-controlled area to the hydrolysate storage area energetics hydrolysate storage tank (process stream #551). BGCAPP calculations suggest that there is sufficient caustic in the ENS to completely destroy any agent surviving the EBHs. This expectation is further supported by the higher temperature and pressure used in the ENS. Nevertheless, the committee is not aware of any evidence that the system will achieve satisfactory DE criteria. To ensure proper accounting of agent destruction, it would be necessary to determine the residual agent levels in this stream.
Finding 3-4. Complete destruction of augmented agent loadings passing through the EBH/ENS system has not been demonstrated.
Recommendation 3-2. BGCAPP should demonstrate satisfactory destruction efficiency for agent serially treated with caustic under the same conditions as those present in the energetics batch hydrolyzers (EBHs) and the energetics neutralization system at agent loadings equivalent to the highest quantities anticipated to be treated by the EBHs without washout.
2 Resource Conservation and Recovery Act (RCRA) Research, Development and Demonstration (RD&D) Revision 5 Submission, 24915-000-GPE-CGPT-00001, filed with the Kentucky Department for Environmental Protection (KDEP) on February 20, 2014.
3 The metal parts treater treats its process streams at 1,000°F for at least 15 minutes.
4 The RD&D Revision 5 Submission states, “[A]fter demonstrating 99.9999 percent DE [destruction efficiency] for agent hydrolysate, validated process controls and statistical testing may be used in lieu of analyzing all batches of agent hydrolysate” Section 3.2.2, p. 66. It is assumed this concept would apply to each of the DE calculation approaches and measurement would not be needed after the original validation for any waste stream included within the DE calculation.
The third effluent stream from the EBHs is the headspace gas. This stream has the potential to be problematic because it is conceivable that some fraction of the agent will volatilize when it hits the hot caustic of the EBHs instead of being hydrolyzed. This is more of a concern for GB, because it has a higher vapor pressure than VX. If a fraction of the agent were vaporized, it would be transferred to the EBH off-gas treatment system (OTE), instead of being transferred to the ENS.5 The OTE system consists of a scrubber that is designed to remove acidic gases. Removal of other organic compounds will also occur here, but the efficiency will be dependent on their solubility in water, since the scrubber uses aerosolized water droplets to capture contaminants. The water solubility of VX is limited, which suggests that the efficiency of its removal by the OTE may not be high; conversely, GB is water soluble, which suggests a higher removal efficiency for GB in the scrubber. However, the OTE’s agent removal efficiency is not known for either agent. This is important because off-gas from the OTE (stream #8517)6 could contain measurable agent, which would not undergo any further filtration or thermal oxidation before being sent to the carbon filter banks in the Munitions Demilitarization Building (MDB) heating, ventilation, and air conditioning (HVAC) system.
It is worthwhile noting at this point that, as discussed in Chapter 2, the load to the MDB HVAC system has always included agent vaporized into the room air during munition drain processes.7 This is still intended, and committee discussions considered implementation of local, shrouded ventilation around each munition as it is punched and drained to reduce the buildup of agent vapor in the rocket handling system (RHS) and munitions washout system (MWS) rooms, which would more efficiently conduct vapor to the MDB HVAC. The MDB HVAC consists of both the activated carbon filter beds, and the ducting that transports air from different rooms to the carbon beds. The BGCAPP RD&D Permit Revision 5 Submission describes the MDB HVAC system function as maintaining a negative pressure environment in the MDB and a flow of air from areas of low contamination probability to areas of higher contamination probability; these pressure and flow characteristics serve to remove agent from the air prior to discharge to the atmosphere after the air stream has passed through other air pollution control systems, including the OTM and OTE.8 The RD&D Permit Revision 5 Submission, however, also anticipates that that MDB HVAC system controls contaminants that might be released from the process as a point source or as a fugitive emission.9
The fact that the MDB HVAC may receive agent-containing vapor is also recognized by the existing RD&D Permit, in Permit Condition T-11, in that it requires monitoring of the MDB HVAC effluent to ensure no confirmed detectable agent emissions. MDB HVAC effluent monitoring for agent is also required by the Title V Air Quality Permit,10 issued to BGAD on June 6, 2011, for the BGCAPP, which requires that the BGCAPP emissions not exceed the General Population Limits specified by the Centers for Disease Control and Prevention for Lethal Nerve Agent VX and Lethal Nerve Agent GB (6 × 10−7 and 1 × 10−6 mg/m3 respectively) at the BGAD property boundary. In addition, the RD&D Permit Revision 5 Submission anticipates that some agent-contaminated carbon will be generated, in that it provides for the off-site disposal of agent-contaminated carbon from the MDB HVAC filters.11,12 Some of the agent will also likely have deposited onto the surface of the HVAC ducting leading to the carbon filtration beds, representing yet another reservoir into which agent is partitioned. However, this is expected to be on the order of a single molecular layer and, hence, would account for at most a small fraction of the total agent, certainly much less than one part in a million corresponding to the upper limit permissible in achieving 0.999999 DE. Hence, this stream is not further considered in assessing DE.
The fact that agent-bearing vapor from the munitions drain operations are directed to the MDB HVAC suggests that the OTE gaseous effluent could be handled in the same way—that is, sent to the MDB HVAC—and that all agent in the stream not be counted in the DE calculation. Note that this is how the stream was to be handled under the original configuration (with the water washout), because it was not anticipated that a gas waste steam from the EBH entering the OTE and going directly to the MDB HVAC system could contain appreciable quantities of agent. However, increases in the agent loads resulting from washout deletion could make approval of any application for a permit revision problematic.
If BGCAPP could count agent trapped on the carbon filter banks of the MDB HVAC system as destroyed, then agent partitioned into the OTE gaseous effluent stream #8517 would not affect whether BGCAPP achieves DE criteria, because the multiple banks of both particulate (HEPA) filters and activated carbon filtration banks that comprise the MDB HVAC system will capture all of the agent exiting the MDB. However, BGCAPP believes that it would
5 Note that the name of this unit may be confusing in that the EBH off-gas treatment system (OTE) does not receive vapor from the energetics neutralization system (ENS), only the energetics batch hydrolyzer (EBH).
6 There are two effluent streams from the OTE, but the scrubber water, which is sent to the ENS, should not create an issue in that the high caustic in the EBH is expected to hydrolyze agent within this source.
7 E-mail from Kyle Conway, BGCAPP, to Jim Myska, committee study director, on December 8, 2015.
8 RCRA RD&D Revision 5 Submission, 24915-000-GPE-CGPT-00001, filed with KDEP on February 20, 2014, p. 41.
9 Ibid, p. 42.
10 Ibid, pp. 66 and 42.
11 Ibid, p. 74.
12 The committee was not tasked with evaluating whether other BGCAPP environmental permits and documentation (e.g., the National Environmental Policy Act) would need to be amended to accommodate the internal operational changes resulting from washout deletion.
not be allowed to take credit for removal of agent vapor by carbon bank adsorption prior to release of exhaust to the atmosphere because the DE does not allow for removal, only destruction.13 Consequently, the mass of agent in the OTE effluent stream will require measurement for inclusion in the DE calculation.
Finding 3-5. An unknown fraction of agent entering the EBHs during the rocket campaigns may undergo volatilization instead of hydrolysis. Volatilized agent will be processed through the OTE system (stream #8517), which is not designed to destroy agent. Agent escaping the OTE will be removed to the MDB HVAC carbon filter banks, together with fugitive agent emissions from the munition drain processes. Because agent partitioned into these pathways cannot be counted as destroyed, and because BGCAPP believes it is not likely to be allowed to take credit for removal of agent vapor by carbon bank adsorption in the MDB HVAC prior to release of exhaust to the atmosphere, the implementation of washout deletion will require significant permit modifications and has the potential to prevent BGCAPP from achieving DE criteria.
Recommendation 3-3. For all of the gaseous process streams, BGCAPP should rigorously demonstrate that negligible agent is partitioned into the munitions demilitarization building (MDB) heating, ventilation, and air conditioning (HVAC) carbon filter banks under all conditions that could arise during the rocket campaign. BGCAPP should provide for monitoring of the OTE effluent stream (#8517) with analytical sensitivity sufficient to ensure that destruction efficiency criteria are achieved before they enter the MDB HVAC system.
One possible way to address the possible agent vapor would be to process OTE effluent through the OTM, as is planned for the air flows from the agent collection system (ACS) and ENS. The feasibility of this approach would be dependent on the impact on the thermal oxidizer (TOX) of this additional gaseous influent flow. Specifically, the addition of the OTM gaseous effluent to the TOX would increase the total flow rate and reduce the gas residence times in the TOX. However, results from BCAPP modeling of higher residual agent levels retained in projectiles treated in the MPT due to washout deletion estimated that TOX residence times would only decrease to 4.3 seconds for VX and to 2.1 seconds for GB.14 These residence times are substantially longer than the minimum 0.5 second residence time required to ensure agent destruction; for the leaker campaign, the minimum TOX residence time increases to 2 seconds to ensure destruction of polychlorinated biphenyls.15 Because the residence times predicted for the agent are longer than even the very conservative time used for polychlorinated biphenyls, they are highly likely to be sufficient to destroy additional agent. Therefore, based on these BCAPP estimates, there should be sufficient additional TOX capacity available to accommodate additional gaseous influent streams from the OTE effluent. Another possibility would be to add a TOX to the OTE. However, BGCAPP construction has been completed and the plant is entering systemization. The procurement and installation of another major piece of equipment would cause schedule delays. Also, the BGCAPP footprint is small and is already tightly packed with equipment. This could make the installation of an additional piece of equipment problematic. For these reasons, the committee believes that routing OTE effluent through the OTM is preferable to adding a new TOX to the OTE.
Recommendation 3-4. BGCAPP should examine the possibility of routing the gaseous effluent from the OTE (energetics batch hydrolyzer off-gas treatment system) into the OTM (off-gas treatment system). This would eliminate the biggest uncertainties in MOut exiting the munitions demilitarization building (MDB), because it is likely that any agent surviving the OTE would be destroyed in the OTM. The number of gaseous streams from processing units exiting the MDB would be reduced to a single stream—namely, the off-gas from the OTM—and would be less likely to contain significant agent as a result of off-gas passing through the thermal oxidizer.
Before leaving the discussion of agent partitioning into the EBH/ENS units, one additional gaseous effluent stream needs to be considered. The ENS also generates headspace gas that is sent to the OTM, where it is passed through the TOX, the Venturi scrubber, and cyclone. It is very likely that residual agent from the ENS headspace gas would be destroyed in the TOX, and hence, this is unlikely to significantly contribute to the amount of agent in the OTM emissions to the MDB HVAC system (stream #807).
As noted above, the MPT receives drained projectiles from the PHS and pieces of rocket warheads from the EBHs. It is likely that the majority of residual agent on rocket warheads will have been destroyed in the EBHs, although a fraction might survive and be sent to the MPT. With deletion of the washout step, more agent will be sent to the MPT with the drained projectile bodies. The MPT is also to be used to pyrolyze agent in the strainer socks from munitions drain operations, and because larger strainer socks are now planned, this will also be the source of a larger agent load
13 John McArthur, environmental manager, BPBG, “Destruction Efficiency Considerations,” presentation to the committee on September 9, 2015.
14 George Lucier, deputy chief scientist, BPBG, “Impacts of Washout Deletion on Metal Parts Treatment and Thermal Oxidizer;” presentation to the committee on September 9, 2015.
entering the MPT. Therefore, the MPT will now treat more residual agent than planned under the original operating configuration.
While the committee’s initial considerations indicate that the MPT should be able to destroy the additional agent from this source, the fact that the MPT will have to handle more agent will compel analysis of the effluent streams emanating from the MPT, of which there are two. The first is the solid projectile bodies and pieces of rocket warheads treated by the MPT that comprise stream #7652; the treated solids are considered to be agent-free as a consequence of the high MPT treatment temperature and residence times noted above.
The second stream is the gaseous MPT effluent, which is subjected to additional treatment through the OTM. The OTM consists of a TOX, the Venturi scrubber, and a cyclone. Under the original configuration, with munition washout, the OTM received gaseous waste streams from the ACS/toxic storage tank, the ANS, and the ENS, in addition to the gas from the MPT. However, as discussed above, under the new configuration, without washout, the ENS and the MPT will see more agent than originally planned, and, therefore, so will the OTM. Because the overall quantity of agent that now will have to be treated by the OTM is not known, and because the OTM was not specifically designed to destroy agent to the six-nines DE criteria, the three effluent streams from the OTM will need to be measured for agent. To rigorously evaluate the DE, the potential agent contained in the three effluents (gaseous, liquid, and solid) from the OTM would need to be included in the calculation of the total agent effluent from BGCAPP.
The amount of agent present in the gaseous effluent emanating from the OTM is likely to be very low, on account of the very high temperatures in the TOX. Hence, the residual agent in the headspace gases emanating from the ACS, ANS, ENS, and MPT could, possibly, be completely destroyed. If this assessment is correct, then effluent from the OTM would not convey any agent to the MDB HVAC system via stream #807, but this cannot be assumed a priori. However, it is worthwhile noting that pilot or experimental evaluations of the efficacy of the OTM for handling higher quantities of intact agent have not been conducted. Any measureable agent in OTM effluent stream #807 will need to be included in the DE calculation.
The second effluent stream from the OTM is water from the Venturi scrubber that is sent to the aluminum precipitation system (denoted as stream #820). Because this is downstream of the TOX, it is not likely to contain a significant quantity of agent; however, this has not been demonstrated. Calculation of the DE would require measurement of the flow rates of this stream and the concentrations of agent within it. The resulting agent mass flow rates would then need to be included in the overall DE.
Finding 3-6. It is likely that the combination of the MPT and the OTM will completely destroy any agent entering the MPT. However, after washout deletion, the OTM will receive gaseous streams from other sources that may contain more agent than originally planned. It is currently unknown whether the OTM can adequately treat the combined load of all streams after washout deletion.
Recommendation 3-5. BGCAPP should measure solid, gaseous, and liquid effluents from the OTM (off-gas treatment system) during initial projectile campaigns to ensure that these effluents meet the destruction efficiency criteria.
The third effluent stream emanating from the OTM consists of solid waste (stream #804) that will likely consist of particles formed in the TOX, which must periodically be removed. As in the case of the metal scrap from the MPT (stream #7652), this material will have been generated by a very-high-temperature process and, therefore, is very unlikely to contain agent. Stream #804 will thus be handled through the residue handling areas for off-site shipment. This conclusion would have to be documented to the satisfaction of the KDEP through validated process controls, as set forth in the BGCAPP RD&D permit (see footnote 5), and statistical testing. Measurement of agent in this stream for calculation of the DE may be deemed unnecessary.
Finding 3-7. The solid waste stream from the OTM should be agent-free. This conclusion will need to be demonstrated to the Kentucky Department for Environmental Protection based on validated process controls and statistical testing.
BGCAPP is working with KDEP to identify appropriate methods to calculate DE after washout deletion and is considering two alternative approaches for generating valid DE calculations with their attendant measurements. These are referred to as Approach 2 and Approach 3 (Approach 1, discussed above, represented the original plant operation that assumed that nearly all agent would be processed through the ANS and will no longer be applicable after washout deletion). All three approaches are presented graphically in Figure 3-1. In short,
- Approach 2 would evaluate DE by measuring agent mass in the feed and effluent streams in the individual treatment units within BGCAPP, except for the OTE (Figure 3-1, individual units to be measured outlined in the purple boxes).
- Approach 3 would evaluate DE by estimating the mass entering the MDB in the individual munitions or batch or munitions, and by measuring the mass in each waste stream as it leaves the MDB (Figure 3-1, orange box).
Under Approach 2, it is assumed that all agent will be partitioned among three processing units: the ANS (as was originally conceived), the MPT/OTM (considered as a single processing unit), and the ENS. To calculate the DE value as presented in Equation 2, as stipulated by the current RD&D permit, the quantities of agent in the process streams entering (MIn) and exiting (MOut) these processing units must be measured or known.16 By summing MIn values and MOut values for each of the three units, DE could be calculated using a modified version of Equation 2. However, the problem with this approach is that there are no reasonable means for measuring all of the MIn or MOut values.
There are a total of three liquid streams, two gaseous streams, and three solid streams that contribute agent to these processing units (MIn). Liquid effluents from the ACS (entering the ANS), and from the OTE and EBHs (both entering the ENS) would need to be measured for agent concentration and volume to enable calculation of agent mass entering these processing units. Similarly, agent concentrations and volumes would be needed for the gaseous streams entering the OTM from both the ACS and the ENS. Finally, agent mass would need to be measured on projectile bodies entering the MPT from the MWS and the rocket pieces from EBHs, and on filter socks from munitions drain operations. Summing the agent masses from these streams on a per-munition or per-batch basis would provide a total MIn value. However, there are currently no analytical devices in place to accomplish the needed measurements anywhere on the feed side of these units, so determining MIn values would require additional measurement methodologies.
Multiple measurements would also be needed for calculating total agent exiting the MDB (MOut). Liquid streams #451, #820, and #551 generated by the ANS, OTM, and ENS, respectively, would require measurement of agent concentration and total effluent volume in these streams. Measurements of agent concentration and volume would also be required for the gaseous effluent in stream #807 emanating from the OTM. However, unlike liquid effluent from the ANS, ENS, and OTM, the gas-phase streams cannot be impounded, which means that sampling would need to occur in-process. This also means that the gaseous streams cannot be reprocessed for additional treatment if necessary. These factors will further complicate measurement of MOut under Approach 3 (see below).
Finally, residual agent mass on the metal generated by the MPT (stream #7652) would need to be measured, although it may be possible to replace measurement with process knowledge based on previous experience that has shown that metal parts subjected to high temperature treatment (1,000°F) for 15 minutes contain no agent. Residual agent mass on the particulate matter from the OTM (stream #804) would also need to be measured, or deemed zero based on process knowledge. Summing the agent masses from these solid streams, together with the liquid stream #820 and the gaseous stream #807 exiting the MDB, would provide a valid MOut value.
A concern with Approach 2 is that it does not account for any agent that survives the EBHs and escapes the OTE to the MDB HVAC system. This could occur because the vapor pressure of GB is high at the operating temperature of the caustic in the EBHs, so volatilization may be competitive with hydrolysis. While the capacity of the carbon filtration system is likely adequate to capture fugitive agent that has escaped the OTE, the quantity of agent that might be partitioned in this effluent stream will not be known. If the state of Kentucky does not allow carbon capture in the MDB HVAC system to count for agent destruction, this factor could impact the ability of BGCAPP to meet the DE criteria.
Finding 3-8. Approach 2 is not an appropriate option for the calculation of DE. It is incomplete because it does not include the gaseous emissions from the OTE—which, under the new configuration, may contain agent—and because it is not operationally practical to measure agent quantities in the feed to, and effluent from, the individual process units.
Under Approach 3 the overall process flow for calculating DE is considered to have a single point of agent entry—that is, intact projectiles or rockets entering the MDB. Thus, it is not necessary to measure the agent masses, concentrations, or volumes at the entry points for each of the process units, because MIn values could be readily estimated, with a reasonable degree of accuracy, from process knowledge of the quantity of agent in each type of munition and the number of munitions to be processed per batch or per unit time. The partitioning of agent through the various units and their effluent streams is identical to that found in Approach 2, so all the considerations for measuring the contributions of the different streams to MOut are the same, except Approach 3 accounts for the possibility that vaporized agent might be transferred to the OTE. The gaseous effluent stream from the OTE (stream #8517) could contain measurable agent and is sent to the carbon filter banks in the MDB HVAC system.
Summing the MOut values produced by these streams, together with the derived MIn value, would be sufficient to calculate a rigorous and defendable DE value in accord with the KRS and RD&D permit requirements,17 using the following modified DE calculation to account for the partitioning of agent resulting from the deletion of agent washout:
16 RD&D permit.
17 John McArthur, environmental manager, BPBG, “Destruction Efficiency Considerations,” presentation to the committee on September 9, 2015.
= the mass of agent input to the agent demilitarization area, presumably to be calculated as the product of the concentration and the volume or mass of the projectile or batch;
= the mass of agent in the liquid effluent from the ANS, calculated as the product of the concentration and the volume;
= the mass of agent in the liquid effluent from the ENS, calculated as the product of the concentration and the volume;
= the mass of agent in the liquid effluent from the OTM, calculated as the product of the concentration and the volume;
= the mass of agent in the gaseous effluent from the OTM, calculated as the product of the concentration and the volume;
= the mass of agent in the gaseous effluent from the OTE, calculated as the product of the concentration and the volume;
= the mass of agent residual on the metal parts from the MPT;
= the mass of agent on the particulate from the OTM TOX unit; and
= the mass of agent in the gaseous effluent from the PHS, MWS, RHS, and other fugitive agent vapor releases that are directed to the MDB HVAC.
This approach is shown in Figure 3-2. The practicality of this approach depends on the methods used to measure agent mass in these solid-, liquid-, and gas-phase streams. Measurement of agent concentrations and volumes in the liquid waste streams could be achieved using the approach
currently used for the ANS effluent. The quantity of residual agent on the metal parts from the MPT is expected to be negligible based on the temperatures and treatment times used and historical knowledge of agent destruction under these conditions. However, the amount of agent on the particles from the OTM will need to be measured. Moreover the gaseous waste streams from the ANS and the OTM will need to be sampled and analyzed for agent at levels sufficiently low to ensure that six-nines criterion is met. A drawback to this approach is that, if the gas-phase streams are found to contain agent, they will not have been held in containment and, thus, cannot be re-processed if additional agent destruction is needed. Thus, for both Approaches 2 and 3, the risk of not meeting the DE criteria is increased due to the uncertain amounts of agent that will be partitioned to the EBH and ENS/ENR, the potential fraction of this agent that will vaporize, the potential fraction of vaporized agent that will be sent to the OTE, and the timescales over which a process or facility response to these events must occur. Such details have not yet been finalized by BGCAPP.
Finding 3-9. Approach 3 could conceivably be used for a defendable DE determination, because it accounts for the OTE gaseous process stream #8517, provided it is modified to include the fugitive releases of agent vapor directed to the MDB HVAC system. However, Approach 3 would require development of additional methodologies for measuring masses of agent partitioned into the two gaseous waste streams entering the MDB HVAC system.
Recommendation 3-6. If Approach 3 is adopted, then BGCAPP should evaluate the concentrations of agent liable to be present in all gaseous process streams and develop measurement approaches with sufficient sensitivity to ensure that destruction efficiency criteria are being achieved.
Approaches 1, 2, and 3 for calculating DE; the potential for increased agent in the process streams after washout deletion; and the committee’s recommended approach to calculating DE with rerouting the OTE off-gas through the OTM are summarized in Table 3-1.
|Stream||Source||Phase||Approach 1 (Original Design, Including Washout)||Potential for Increased Agent (No Washout)||Approach 2 (No Washout)||Approach 3 (No Washout)||Committee-Recommended Approach (OTE Routed to OTM, No Washout)|
|n/a||Input, combined MPT/OTM||Gas||Y||Measure|
|n/a||Input, combined MPT/OTM||Solid||Y||Measure|
|n/a||Output, ventilation from PHS, MWS and RHS (to HVAC)||Gas||Y||Measure|
a Stream identification numbers are found in Figures 3-1 and 3-2. Stream measurement is identified for each of the DE calculation approaches. The potential for increased agent in the streams is also indicated. The final column addresses changes in measurement if the gaseous streams from the OTE are sent to the OTM.
NOTE: ANS, agent neutralization system; ENS, energetics neutralization system; HVAC, heating, ventilation, and air conditioning; MPT, metal parts treater; MWS, munitions washout system; PHS, projectile handling system; OTE, EBH off-gas treatment system; OTM, off-gas treatment system; RHS, rocket handling system.
As noted, one of the major limitations in calculating a valid DE after washout deletion is the increased number of measurements that will be needed compared to BGCAPP’s original plan. Under its RCRA permit, BGCAPP will have to establish these analytical methodologies for measuring agent in the individual waste streams in its waste analysis plan and use such results to conduct the DE calculation for each initial batch of agent to be treated in the BGCAPP, as required under the KRS and the KAR.
The analytical measurement approach that was based on the original operational design to ascertain that the concentration met the six-nines DE criterion in the ANS liquid effluent will likely be applicable to the liquid waste streams from the OTM and the ENS under the modified operational design that no longer includes munition washout. However, clearance levels for the three liquid streams will vary depending on the fraction of agent partitioned into the ANS, MPT, and EBHs. At the present time, the fraction of agent that will be partitioned into these processing units is not known. However, a measurement of the concentration, together with a reasonable estimate of the volume produced per munition or per batch, will suffice to provide defendable MOut values in the three liquid effluent streams. BGCAPP will have to determine whether the sensitivity of the current methodology will be sufficient to confirm that DE criteria have been met.
As stated above, it is likely that new methods for measuring agent on metal parts from the MPT will not have to be developed. This is based on the expectation that it can be reasonably demonstrated from historical data and process knowledge that agent subjected to the temperatures and residence times in the MPT will be completely destroyed. Unless it can be demonstrated that current methods are capable of measuring agent in the particulate matter generated in the OTM TOX, new methods will need to be developed for measuring that process stream.
The gaseous process stream from the OTM is also not likely to contain significant agent, based on historical experience of the DE in units similar to the TOX. However, the same statement does not apply to the gaseous effluent from the OTE. The fraction of intact agent that will be partitioned into the off-gas stream from the OTE is not known; however, the fraction partitioned will affect the analytical requirements for this stream and the methodology eventually settled on.
Finding 3-10. The performance requirements for the analytical measurement methodology for measuring agent in the off-gas process stream from the OTE (#8517) are not known, because the fraction of agent that will be partitioned into this stream is uncertain.
Recommendation 3-7. If Recommendation 3-4 is not pursued, BGCAPP should conduct research to determine what fraction of GB agent might partition into the off-gas process stream from the OTE (energetics batch hydrolyzer off-gas treatment system) and then use this information to set analytical performance requirements that can be used to identify analytical measurement methodology.
Note, the committee considered whether a revision to the DE equation in the KAR would be possible that would allow for only measuring the DE at the final exhaust of the MDB HVAC system—in essence, including the removal of agent onto the carbon filters as the final step in treatment (i.e., destruction and removal efficiency). However, the committee could not determine the ability of BGCAPP to predict that the agent in the final exhaust from the MDB HVAC system would always meet the statutory requirement that the treatment or destruction technology has been demonstrated as effective in order to provide assurance of destruction or neutralization at an efficiency of 99.9999 percent for each compound under all operating conditions.