One of the last sites with a stockpile of chemical munitions is the Blue Grass Army Depot (BGAD), located near Richmond, Kentucky. The stockpile at BGAD consists of rockets and projectiles that contain the nerve agents GB (sarin) and VX and the blister agent mustard. The rockets also contain energetics, including a burster explosive and propellant. Under the direction of the Program Executive Office (PEO) for Assembled Chemical Weapons Alternatives (ACWA), the Blue Grass Chemical Agent Destruction Pilot Plant (BGCAPP) is in the final stages of construction and will destroy the munitions containing GB and VX.1,2
Destruction of the chemical weapons is mandated by the Chemical Weapons Convention (CWC).3 BGCAPP operations will be overseen by the Kentucky Department for Environmental Protection (KDEP), which administers the environmental permits under which BGCAPP must operate. Additional BGCAPP stakeholders include the public, represented by the Kentucky Citizens’ Advisory Commission (CAC) and the Chemical Destruction Community Advisory Board (CDCAB).
Caustic hydrolysis will be used at BGCAPP to destroy the agents and energetics, resulting in a secondary waste stream known as hydrolysate. A first-of-a-kind (FOAK) technology, supercritical water oxidation (SCWO), will be used to treat the hydrolysates. SCWO will mineralize organic materials in the hydrolysates by reacting them in water above its critical temperature and pressure (Tc = 705°F, Pc = 218 atm (3,200 psi)). SCWO effluent will then be sent to a water recovery system (WRS) that will use reverse osmosis (RO) to separate salts from water. The end products of the SCWO and WRS processes are water and brine. The water is intended for reuse as SCWO quench water, reducing the amount of water needed from onsite sources. The brine will be sent offsite for disposal. Treatment processes are detailed in Chapter 2.
Considering the FOAK nature of SCWO and the complexity of the hydrolysate, ACWA has been concerned that SCWO and WRS may not function as designed. ACWA commissioned two earlier National Research Council studies of the BGCAPP systems, one for the WRS, completed in 2012, and another for SCWO, completed in 2013.4 The authoring committees made a number of recommendations, but there were no overarching concerns that the processes would not work, assuming their recommendations were adequately addressed. ACWA has commissioned this study by a committee of the National Academies of Sciences, Engineering, and Medicine5 to further examine the possibility of delay or failure of the SCWO or WRS and to examine possible alternatives to onsite treatment. The Statement of Task for this study is provided in Chapter 1.
As discussed in Chapters 6 and 7 of this report, BGCAPP will conduct preoperational testing concurrent with facility systemization intended to identify and resolve problems with equipment and operating procedures. This testing is expected to increase the likelihood of success. However, underperformance or failure of the SCWO and/or WRS could result in BGCAPP not meeting its overall performance criteria, as set forth in Chapter 6. The remainder of this Summary discusses the content of the report, directing the reader to the pertinent chapters for more detailed discussion, and presents selected findings and recommendations that highlight what the committee believes are the key points of the report. Also,
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1 BGCAPP is called a pilot plant because some of the processes used for destroying the agent have never before been used in this application, or used in combination with each other.
2 The mustard stockpile at BGAD will be disposed of onsite using an explosive destruction technology; it will not be processed through BGCAPP.
3 Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on Their Destruction. The treaty entered into force in 1997.
4Letter Report: The Blue Grass Chemical Agent Destruction Pilot Plant’s Water Recovery System, 2012, and Assessment of Supercritical Water Oxidation System Testing for the Blue Grass Chemical Agent Destruction Pilot Plant, 2013 (NRC, 2012; 2013).
5 Effective July 1, 2015, this institution, formerly sometimes referred to as the National Research Council, is called the National Academies of Sciences, Engineering, and Medicine.
as explained in Chapter 1, the committee did not develop original success criteria for the SCWO and WRS as called for in the statement of task. While new criteria could be developed, these should be based on preoperational testing and systemization, which for BGCAPP has yet to be initiated. In the course of its work, this committee received briefings from PEO ACWA, BGCAPP staff, public stakeholders, and KDEP during its January 2015 meeting in Kentucky, which took place at two locations near BGCAPP. The committee has since reviewed extensive documentation on the BGCAPP processes and engaged in significant back and forth with BGCAPP staff and public stakeholders.
Finding 1-1. It is expected that extensive preoperational testing of the SCWO and the WRS will be performed concurrently with systemization to help reduce the uncertainty in expected technological performance. However, considering the first-of-a-kind nature of these technologies and the need for them to properly function in tandem, there is a possibility that technological issues with these systems may prevent BGCAPP from meeting all of its overall performance criteria.
Chapter 7 provides a detailed discussion of technical factors that may lead to underperformance of the SCWO or WRS. If problems occur, the hydrolysis process may have to be interrupted. In the event that hydrolysis is halted, and as hydrolysate storage nears capacity, destruction of the stockpile at BGAD may need to be halted unless there is an alternative means for treating the hydrolysate. The nerve agent munitions at BGAD have been stored for over 50 years. Delays in the destruction process will protract the risk to the community associated with continued storage. The committee believes that destruction of the BGAD stockpile must continue to eliminate the risk. Hence, the committee believes it is necessary to establish a backup plan.
Recommendation 1-1. Considering that the SCWO and the WRS may not perform satisfactorily and that this underperformance could result in delays in the destruction of chemical agent at BGCAPP, increasing the primary risk to the community associated with continued munitions storage, BGCAPP should establish a backup plan as an alternative to the onsite hydrolysate treatment processes.
Should SCWO or WRS problems develop, substantial storage capacity exists at BGCAPP, allowing time to improve performance while agent destruction continues. Hence, the likely scenario if issues develop would be that BGCAPP would have time to resolve any SCWO or WRS problems as neutralization continues. Only if hydrolysate storage nears capacity, or if problems appear unsolvable, would it become necessary to consider the backup plan. One alternative that would likely be more readily implemented than others would be to ship the hydrolysate offsite for treatment and disposal.
Further, if the WRS underperforms or fails, neutralization and SCWO operations could continue as long as BGCAPP can obtain permits to withdraw additional water from local sources for SCWO reactor quenching. BGCAPP would then need to seek alternative means of disposal of the SCWO effluent. Alternatively, BGCAPP could forgo SCWO and send the hydrolysate offsite instead. Continuing SCWO operations would destroy compounds regulated by the CWC, obviating further oversight by the Organisation for the Prohibition of Chemical Weapons (OPCW) if untreated hydrolysate were to be shipped offsite. This option, however, would entail a significant increase in offsite waste shipments, as discussed in Chapter 5. The benefits of further CWC oversight will need to be considered against the costs of increased waste shipments.
The choices that will be faced with possible underperformance of SCWO or the WRS are highly complex. All alternatives will entail interconnected considerations about technological capabilities and limitations, in conjunction with PEO ACWA commitments, contractual requirements, public stakeholder opinion, regulatory permitting requirements, schedule delays, and cost.
STAKEHOLDER CONCERNS
The concerns of the community are a key consideration in any offsite decision process. The community around BGCAPP is represented primarily by the CAC and the CDCAB. The CAC comprises nine members appointed by the state governor. An independent CAC subcommittee, the CDCAB, provides for broader stakeholder involvement from local organizations including medical, emergency management, university, and school representatives.
The committee held its first meeting in Richmond, Kentucky, in January 2015 and invited CAC/CDCAB members to attend. The committee also held a separate public meeting during the January 2015 sessions. The CAC chair and one co-chair of the CDCAB attended the 2-day open meetings and also attended the public meeting.6 As part of the discussions and presentations at the meeting, the CAC/CDCAB provided written and verbal statements of their views on the conduct of the study, including criteria that they believe should guide decisions regarding potential offsite shipment. Several conference calls were also conducted, both with CAC/CDCAB representatives and with PEO ACWA and BGCAPP public involvement officials. As a result of these activities, the committee learned that despite initial conflicts, the CAC/CDCAB, PEO ACWA, and BGCAPP have built a solid working relationship. Should operational issues arise at BGCAPP this working relationship will provide a strong basis for continued and meaningful public involvement.
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6 The position of the second co-chair was in transition at the time of the committee’s site visit.
The CAC/CDCAB recognizes that the weapons at BGAD must be destroyed as soon as and as safely as possible. They view onsite treatment with hydrolysis followed by the SCWO and WRS technologies as a commitment made to the community. As documented in previous reports the CAC/CDCAB opposed offsite hydrolysate shipment in the past (NRC, 2008; Noblis, 2008; NRC, 2012). They nevertheless recognize that there are bound to be issues with a pilot plant such as BGCAPP and that failure of key processes could force an examination of alternatives. The CAC/CDCAB maintain that offsite hydrolysate shipment would only be acceptable if it were the sole alternative, and should be temporary until BGCAPP systems are back online. Most important for the CAC/CDCAB, however, is that they continue to be involved in the decision process.
Recommendation 3-1. In collaboration with the CAC/CDCAB, the Program Executive Office for Assembled Chemical Weapons Alternatives should institutionalize a transparent consultation process that builds on the existing foundation and working group structure to ensure meaningful stakeholder input into analyses, evaluations, and decision criteria related to potential offsite shipment of hydrolysate and that provides opportunities for engaging with communities that would receive hydrolysate.
REGULATORY ISSUES
Chapter 4 discusses regulatory requirements for potential offsite shipment of hydrolysate or SCWO effluent. Applicable regulations include the Resource Conservation and Recovery Act (RCRA), as administered by KDEP and the U.S. Environmental Protection Agency, and the National Environmental Policy Act (NEPA). There are also state and local requirements regarding the transport of hazardous materials, and also water withdrawal permits that need to be considered. In addition, the requirements of the CWC, as administered by the OPCW, need to be considered.
RCRA permitting requirements provide the greatest challenge for BGCAPP. The challenge is made greater by the unique situation in Kentucky, where legislation establishes hazardous waste listings for the chemical agents. The legislative language pertaining to chemical agent would classify waste derivatives such as hydrolysate and SCWO effluent as acutely toxic wastes, the same as the original agent. This acute toxicity designation imposes stringent requirements for management of these wastes that are burdensome and unnecessary. The CAC/CDCAB, in coordination with BGCAPP, are presently pursuing legislative changes that would alleviate this situation.
Another complication in Kentucky stems from the manner in which the BGCAPP RCRA permit is structured. BGCAPP is permitted under a RCRA Research Development and Demonstration (RD&D) permit for destruction of GB, but is intended to switch to a conventional RCRA Part B permit for destruction of the VX. Should SCWO be abandoned during the RD&D phase, the RD&D permit would no longer be applicable and BGCAPP would have to switch to a Part B permit. More important, should hydrolysate or even SCWO effluent need to be shipped offsite, under either the RD&D or a Part B permit, a year or more would likely be needed to process the required permit modifications.
Recommendation 4-4. As a backup plan, BGCAPP should revise its RCRA Part B permit application currently being prepared for the disposal of VX munitions to allow for the possibility of offsite transport of VX agent, GB agent, and energetics hydrolysates, as well as spent decontamination solution and SCWO effluent should the SCWO or WRS process be shown to be irreparable.
Recommendation 4-5. As a backup plan, BGCAPP should consult with KDEP concerning whether the RCRA RD&D permit could be modified to allow the temporary offsite transport of GB hydrolysate (i.e., until the SCWO can be brought back on line) or for the temporary or permanent offsite transport of SCWO effluent should the WRS process be shown to be irreparable.
Further, NEPA documentation may be required to support transporting hydrolysate or SCWO effluent offsite. The option to transport these materials for treatment and disposal was not directly considered in the BGCAPP NEPA analyses that have been conducted. The NEPA process could also be lengthy and may also take many months if it becomes necessary to produce additional documentation.
The key point is that regulatory delays not impact the destruction of agent at BGCAPP. Accordingly, the committee believes that RCRA permit modifications and NEPA documentation that support the potential for offsite shipment as a backup plan need to be prepared expeditiously and discussed with all stakeholders.
TRANSPORTATION ASSESSMENT
One of the concerns regarding potential offsite transportation is the risk of a transportation crash or release incident. Chapter 5 summarizes previous offsite shipments from chemical demilitarization facilities. That summary demonstrates that hydrolysate and similar fluids have been shipped offsite from a number of locations without incident many times in the past.
That is not to say that a transportation crash or incident could not occur, however. But it is important to understand that the hazard posed by hydrolysate is not from the presence of agent within the hydrolysate: During the hydrolysis process, the agent is destroyed, and destruction is verified prior to SCWO treatment. Although the presence of agent degradation products, including CWC schedule 1 and 2 chemicals, is a concern, the primary hazard of a release
of hydrolysate during transportation would come from its causticity. BGCAPP hydrolysate would be considered a Department of Transportation Class 8 (corrosive) material.7 The hazards due to hydrolysate exposure are modest compared to exposure to materials such as concentrated sodium hydroxide, a typical Class 8 material.
There is also a possibility, as indicated in Chapters 4, 6, and 7, that SCWO effluent could be sent offsite. If SCWO effluent is sent offsite for further treatment or disposal, the hazard posed by this material itself would be minimal. The effluent is a non-toxic brine. The main risk of SCWO effluent shipment would come from a substantial increase in the number of offsite shipments and the associated increase in the likelihood of a crash.
While the committee believes that the transport of hydrolysate or SCWO effluent would be low-risk, it is desirable that PEO ACWA perform a quantitative transportation risk assessment, including a quantitative assessment of the human health consequences if there is a release of hydrolysate or SCWO effluent. It is also desirable that PEO ACWA prepare a prototypical emergency response plan. These documents will help facilitate discussions with the public and regulators about possible offsite shipment. As with regulatory documentation, the transportation assessment and emergency response plan should be prepared as a backup plan and be ready to go if it is determined that offsite transport of hydrolysate or SCWO effluent is needed.
CRITERIA FOR SUCCESSFUL HYDROLYSATE TREATMENT AND DECISION FRAMEWORK
Chapter 6 presents treatment criteria for agent and energetic hydrolysates and provides a framework for decision making. Two categories of criteria are defined in Chapter 6:
- Performance requirements. Conditions that must be met under regulatory permits and under CWC treaty obligations, and
- Performance goals. Primarily oriented toward process performance and schedule and should be met to enable satisfactory system performance.
Performance requirements are crucial in achieving successful BGCAPP operation. If these requirements cannot be met, and if the time it takes to destroy munitions increases, risk reduction goals will not be achieved in a timely manner, and the offsite hydrolysate option becomes a more attractive option.
Finding 6-1. The primary criteria for successful treatment of hydrolysate involve meeting regulatory and Chemical Weapons Convention requirements and meeting process performance and schedule goals for hydrolysate treatment.
Performance goals consist mostly of quantitative expectations for SCWO and WRS performance. These goals are based on the results of past testing, modeling, and analysis by BGCAPP and its contractors. The committee anticipates that these goals may be modified during preoperational testing. A failure to meet some or many of the goals, while it may impact process performance, schedule, and costs, would not necessarily result in offsite shipment. However, if modifications made during systemization to achieve these goals do not result in improved performance, then consideration of offsite transport becomes more likely.
Recommendation 6-1. The ability to meet the initial performance goals established by BGCAPP for SCWO and the WRS should be verified as a result of testing during systemization.
Chapter 6 provides an example of graded evaluation to evaluate potential for success of SCWO and the WRS as the project proceeds toward completion. This is shown in Table S-1 (also Table 6-1).
| Grade | Definition | |||
| 0 | Success is practically certain (very low probability of SCWO or WRS failure): Operations are proceeding as expected. No BGCAPP actions needed. | |||
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1 |
High likelihood of success (low probability of SCWO or WRS failure): Actions should be taken by BGCAPP to prepare ahead of time for implementation of contingencies in the event of failures. For example, BGCAPP might begin to prepare permit modifications and planning documents. |
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2 |
Success is uncertain (moderate probability of SCWO or WRS failure): Actions should be taken to prepare for implementation of contingency operations. For example, BGCAPP might begin processing environmental documentation (permit modifications) and finalizing contingency plans and begin to initiate changes in infrastructure to permit off-site shipment. |
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3 |
Success is unlikely with current operations (high probability of failure of the SCWO or the WRS): Actions are taken to accelerate the implementation of contingency operations and stakeholders are consulted. For example, construction of needed facilities such as new piping and loading docks is completed as quickly as possible, environmental approvals are expedited, if not already obtained, and contracts for shipment offsite and disposal at a permitted treatment, storage, and disposal facility are signed. |
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7 Class 8 hazmat is defined in 49 CFR 173.136 as a liquid or solid that causes (1) full thickness destruction of human skin within a specified period of time or (2) a specified corrosion rate of steel or aluminum.
Once hydrolysate processing begins, adjustments to SCWO and WRS operating procedures, process chemistry, and equipment will be made as needed. If the SCWO and the WRS fail to satisfy regulatory requirements and performance goals despite these adjustments, offsite hydrolysate shipment becomes more likely.
UNDERPERFORMANCE AND FAILURE RISKS, SYSTEMIZATION, AND CONTINGENCY OPTIONS
Chapter 7 discusses the possible risks of underperformance or failure of SCWO and WRS and focuses on decisions leading to possible changes in plant operations. The decision framework, the performance criteria, and the graded scale for success introduced in Chapter 6 are used in the discussion of these risks. The possibility of multicomponent failure is also discussed in Chapter 7.
Underperformance and Failure Risks, Systemization, and Contingency Options for the Supercritical Water Oxidation System
SCWO can irreversibly break down organic compounds using only oxygen, water, and supplementary fuel. Based on research and development of SCWO systems, including FOAK testing on simulated hydrolysates, BGCAPP scientists and engineers have identified a number of challenges that may be encountered in the operation of the SCWO system at BGCAPP and are taking appropriate corrective actions to address these challenges (BPBG, 2013).
Finding 7-1. BGCAPP scientists and engineers have identified a number of challenges that may be encountered in the operation of the SCWO system at BGCAPP and are taking appropriate corrective actions to address these challenges.
Nevertheless, the SCWO system has a number of components that all have to operate in unison. First, agent hydrolysate and energetics hydrolysate (after aluminum removal) are mixed along with specific amounts of various additives in the blend tank. In addition to requiring specific blend ratios of energetics hydrolysate to agent hydrolysate in the SCWO feed system, salt management is critical. Successful SCWO operation during agent processing will require close monitoring of feed composition with each feed campaign to ensure the target additive concentrations are reached prior to feeding the mixtures to the SCWO reactors.
Finding 7-4. The SCWO system is complex and has a number of components, all of which have to operate in unison for hydrolysate to be effectively destroyed in a timely manner.
Technical factors that may affect SCWO performance will be addressed during preoperational testing activities carried out during systemization. A Blue Grass SCWO Working Group was formed in April 2014 to address issues related to SCWO performance. The SCWO Working Group is addressing the gaps in knowledge, experience, and performance of the SCWO process, providing recommendations for closing these gaps, and producing a plan for implementing these recommendations. With this approach, the likelihood of reliable SCWO operations should be greatly enhanced.
Recommendation 7-3. The SCWO Working Group plan, as described in the December 17, 2014, Systemization Planning Report, and recommendations for correcting potential gaps in the October 27, 2014, Working Group report should be aggressively implemented. Furthermore, the SCWO Working Group should continue to provide support to all risk mitigation activities involving SCWO operations at BGCAPP.
While FOAK testing established reactor downtimes and maintenance cycles, these tests were only conducted on simulated hydrolysate streams and were conducted over relatively short periods of time compared to the expected 3-year destruction schedule at BGCAPP. There are contingency options if the SCWO does not meet performance requirements and goals, including materiel and procedural options. These are summarized in Table 7-1. If performance requirements and goals cannot be met consistently and satisfactorily, it may become necessary to consider shipping some or all of the hydrolysate or SCWO effluent offsite for disposal elsewhere.
Underperformance and Failure Risks, Systemization, and Contingency Options for the Water Recovery System
The WRS consists of three SCWO effluent storage tanks, a pretreatment system to remove suspended solids, three RO units (two in operation, one in reserve), two storage tanks for RO permeate, and two storage tanks for RO reject. The WRS influent will comprise two combined streams: (1) SCWO effluent and (2) cooling tower and steam blowdown water. These streams will be high in total dissolved solids, making RO an attractive process for treating the water so that it can be reused as quench water for the SCWO reactors. Although RO is an established treatment technology for high total dissolved solids waters, the SCWO effluent is a unique feed for RO and poses some treatment challenges. A prior National Research Council committee (2012) expressed the following concerns associated with the WRS system:
- Possible overloading of the pretreatment multimedia filters with particles from the SCWO process, including titanium dioxide, iron oxides, and calcium and aluminum phosphate precipitates;
- Potential for RO fouling and scaling due to inadequate pretreatment by the coagulation and direct filtration processes; and
- Durability of the materials of construction.
The committee believes that concerns expressed in the previous letter report have not been completely addressed in the current WRS design. The committee also believes that uncertainties associated with solids loading and coagulant requirements need to be addressed. It would be very useful for WRS performance to be assessed during pre-operational testing using realistic SCWO effluent simulants. These tests would ideally also establish operational conditions for effective filtration. If the influent solids concentration is too high, or if the actual loading threshold is far less than the design loading threshold, the filters could require frequent backwashing, increasing the demand for an alternative source of clean backwash water. The absence of a clarifier ahead of the filters increases the likelihood of overloading the filters with suspended solids.
Preoperational testing would also ideally test the effectiveness of inorganic coagulants for treating SCWO effluent and determine the exact conditions for effective coagulation. Further, it is uncertain how TiO2 solids emanating from corrosion of the SCWO liner will respond to coagulation. Another potential problem is the volume and quality of water to backwash the filters. The SCWO effluent, the proposed source of backwash water, is expected to have a high suspended solids concentration, making this water source less than optimal for backwash water. A better option for backwash water for the multimedia filters would be the filter effluent itself.
Finding 7-13. Since many WRS process details are unknown, including the amount of solids in the SCWO effluent, the amount of solids that settle in the SCWO effluent storage tanks, and coagulant requirements and effectiveness, successful operation of the current WRS direct filtration multimedia pretreatment system is uncertain. Therefore, successful operation of the RO units is uncertain.
Recommendation 7-8. Well-planned preoperational testing should be performed with actual SCWO effluent, or a realistic simulant, to establish operating conditions for effective pretreatment and to determine if the WRS system, especially the multimedia direct filtration system, will perform as expected. In particular, preoperational testing should determine the solids loading and corresponding coagulant requirements for effective pretreatment. As noted in Chapter 6, serious consideration should be given to forming a WRS working group analogous to the SCWO Working Group.
In addition, the successful operation of the SCWO process for destruction of the agent hydrolysates is tightly linked to the production of quench water from the WRS units. If the WRS were unable to provide adequate quench water, another source of quench water for the SCWO system would be needed. There are contingency options if the WRS does not meet performance requirements and goals. These are summarized in Table 7-2. The challenge of complete WRS failure would be the need to seek alternative treatment or disposal of the SCWO effluent, which could involve an onsite process but, more likely, would entail offsite treatment or disposal.
Offsite Shipment as a Contingency Option
Chapter 7 discusses a number of potential modifications to SCWO and the WRS, weighing the causes and impacts of failure against the onsite contingency options. However, there may be scenarios in which SCWO system underperformance is so severe, compounded, or chronic that onsite mitigation actions are no longer sufficient. In this case, offsite shipment of hydrolysate would need to be considered. On the other hand, if the SCWO system performs adequately but the WRS underperforms or fails, there may be work arounds that enable BGCAPP to continue the destruction of hydrolysates using SCWO. In this case, BGCAPP would have the option to continue SCWO operations and send SCWO effluent offsite or halt both SCWO and WRS operations and send hydrolysate offsite. Continuing SCWO operations would meet CWC requirements and obviate the need for further OPCW oversight of hydrolysate sent offsite. Per Chapter 5, however, sending SCWO effluent offsite would substantially increase the number of offsite waste shipments. The resource requirements for increased offsite shipment would need to be carefully evaluated against the alleviation of further CWC oversight associated with continuing SCWO operations.
Should the decision be made to ship hydrolysate or SCWO effluent offsite, additional infrastructure would be needed to efficiently and effectively transfer the material for shipment. Infrastructure additions would likely be minimal but might include additional piping, leak containment, agent monitors, waste loading areas, truck loading docks, new rail/roadways onsite, new signage, and extra traffic controls at BGCAPP. As discussed in Chapter 5, shipping the hydrolysates offsite would actually produce fewer truckloads of hazardous waste material requiring disposal than the current plan.
Finding 7-16. A decision to ship hydrolysate offsite could have serious impacts on stakeholders, BGCAPP operations, regulatory compliance, and obligatory requirements under the Chemical Weapons Convention. There might be additional negative impacts if BGCAPP is not prepared ahead of time for a possible transition to offsite shipment, if and when such a decision is made.
The agent and energetics hydrolysates each have unique chemical compositions. In the current operating plan, the energetics hydrolysate is treated to remove aluminum and then blended with nerve agent hydrolysate prior to SCWO treatment. If offsite shipment is implemented, the committee believes it would not be necessary to remove aluminum from the energetics hydrolysate prior to offsite shipment, as long as the receiving treatment, storage, and disposal facility is able to accept the hydrolysate as is. It would also be just as
acceptable to ship the hydrolysates separately as it would be to ship them after blending.
The committee also deliberated at length on whether the decision to ship offsite should be permanent, or if there are scenarios in which offsite shipment could be used temporarily or in parallel while the SCWO system and WRS operate at reduced availability. Implementing offsite transport of hydrolysate under any circumstance (temporary, parallel, or permanent) would affect plant, paper (e.g. regulatory permit modification), and people, as discussed in Chapter 7. Physical changes to the plant, changes in permit documentation and standard operating procedures, the conduct of transportation risk assessments, and staffing changes would need to be considered, just to name a few examples. Any effort to implement offsite transport would be considerable. Likewise, the effort to shift back to onsite treatment would also be substantial.
Offsite shipment in parallel with reduced onsite hydrolysate treatment might alleviate some of the transition burdens, but the scenarios in which this option is practical are limited. Also, operating SCWO at reduced capacity while also shipping some hydrolysate offsite would increase the system management burdens, in addition to those efforts required to repair the underperforming component(s). The committee acknowledges that at this time it is not possible to predict the exact circumstances of SCWO or WRS underperformance or failure once BGCAPP enters into operation and that the evaluation of whether to ship offsite permanently, temporarily, or in a parallel manner is more appropriately made by decision makers and stakeholders when the specific circumstances are known.
Throughout the report, the committee recommends that BGCAPP take actions, such as filing the necessary permit modifications and installing shipping infrastructure, necessary to prepare for the last-resort decision to ship hydrolysate offsite in order to avoid further delay in munitions processing. However, the committee also recognizes the tension that would be created in the decision process if these measures are implemented before they are needed. Making these preparations beforehand should in no way bias the decision in favor of offsite shipment. In the event that offsite shipment needs to be considered, the decision needs to be based on the application of an established decision framework and appropriate consultation with stakeholders.
Finding 7-18. The SCWO system to be used at BGCAPP has been subjected to numerous tests with hydrolysate simulants and appears to be a mature technology. Likewise, the RO system at the heart of the WRS is a proven technology for desalinating water. However, these technologies have not been used with actual hydrolysates in a continuously operating environment for the 3 years during which it is expected to perform at BGCAPP.
Recommendation 7-10. Although the SCWO and WRS appear to be capable of processing hydrolysate at BGCAPP, and a comprehensive preoperational testing program to improve performance will be undertaken, there is still a reasonable possibility that at some point during BGCAPP operations, a decision may need to be made to ship hydrolysate or SCWO effluent offsite. As a precaution, BGCAPP management should prepare for this contingency by taking all necessary actions having long lead times well in advance of such a decision.
REFERENCES
BPBG (Bechtel Parsons Blue Grass). 2013. Test Report for Supercritical Water Oxidation (SCWO) First-of-a-Kind (FOAK) Test (Preliminary Draft). SDN-24915-00-GQY-GGEN-00094. Richmond, Ky.
NOBLIS. 2008. Offsite Disposal of ACWA Hydrolysates. NTR 2008-61129. Falls Church, Va.
NRC (National Research Council). 2008. Review of Secondary Waste Disposal Planning for the Blue Grass and Pueblo Chemical Agent Destruction Pilot Plants. Washington, D.C.: The National Academies Press.
NRC. 2012. Letter Report: The Blue Grass Chemical Agent Destruction Pilot Plant’s Water Recovery System. Washington, D.C.: The National Academies Press.
NRC. 2013. Assessment of Supercritical Water Oxidation System Testing for the Blue Grass Chemical Agent Destruction Pilot Plant. Washington, D.C.: The National Academies Press.
