. "3 Assessment of Metal Parts Treater Testing Activities." Review and Assessment of Developmental Issues Concerning the Metal Parts Treater Design for the Blue Grass Chemical Agent Destruction Pilot Plant. Washington, DC: The National Academies Press, 2008.
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Review and Assessment of Developmental Issues Concerning the Metal Parts Treater Design for the Blue Grass Chemical Agent Destruction Pilot Plant
anticipate halogenated materials and the possible corrosive nature of steam. Also, testing prior to systemization should include halogenated feeds at the rate expected from plant design and operations.
Finding. Inadequate data were collected to serve as the basis for determining processing rates for secondary waste. Waste loading in trays during the TRRP testing may not be representative of loading configurations during operation (e.g., weight per tray, double-stacking, and so on).
Recommendation 3-6. Additional testing is needed to verify the complete destruction of secondary waste and to verify appropriate feed (e.g., tray and loading) configurations that render effective treatment of the variety of types of secondary waste.
Alternative Treatment and Disposition of Secondary Waste
In general, secondary waste can be shipped off-site safely if it meets one of two criteria: (1) if analysis shows levels less than the applicable waste control limits (WCLs)8 or (2) if the waste has been subjected to thermal treatment at 1000°F for 15 minutes. The second criterion, formerly called treatment to 5X, was a requirement for off-site shipment until June 2004 when the WCL criteria were introduced.
The BPBGT plans to heat all secondary waste to 1000°F for at least 15 minutes in the MPT. The advantage of that approach is that documentation is straightforward and no further analysis need be done before shipment. The disadvantage is that many of the secondary waste materials form chars and tars at that temperature that can foul the trays and the OTM.
Permits under the Resource Conservation and Recovery Act of 1976 for baseline incineration facilities generally consider waste to be nonhazardous for chemical agents and suitable for off-site shipment if extractive analysis of the waste shows the concentration of agent to be less than the WCL (NRC, 2007). The analysis can be done using the toxicity characteristic leaching procedure, as described in the Environmental Protection Agency’s publication SW-846, or by using a different methodology approved by the state regulatory agency (NRC, 2007).
In order to be able to use a WCL criterion, the BPBGT would need to get approval from the State of Kentucky on the acceptable WCL for each agent and the method of analysis to be used. If approval is obtained, each secondary waste batch suspected of being agent-free may be tested. If it meets the WCL, it can be shipped off-site with no further treatment. If it does not meet the criterion and is likely to char or tar at 1000°F, it can be treated at a lower temperature in the MPT and the end product can be analyzed to verify that it meets the WCL. By lowering the temperature to ~500° F for 1 to 2 hours, six nines (99.9999 percent) agent destruction and removal efficiency should be achievable, and char and tar formation should be greatly reduced.
Finding. In many cases, secondary waste can be shipped off-site for treatment and disposal in a safe manner.
Finding. For waste that cannot be shipped off-site, the MPT could be used at a lower temperature for treating secondary waste to reduce tar and char load.
Recommendation 3-7. To reduce the technical risks in treating secondary waste in the MPT, the BPBGT should continue to strive to send as much secondary waste off-site as possible, and should obtain the necessary permits to allow lower-temperature processing in the MPT.
Finding. TRRP MPT testing confirms that treatment of metal parts and secondary and closure waste can be performed at 1000°F for 15 minutes in a suitably sized MPT if enough time is allowed for the treatment and if the testing recommended in Recommendation 2-1 is completed.
WCLs and the analytical methods required to demonstrate that they have been achieved vary by state. In general, the WCL is defined as 20 parts per billion (ppb) for GB and VX and 200 ppb for HD, as determined by the Environmental Protection Agency’s (EPA’s) toxicity characteristic leachate procedure (TCLP) applied to the residuals from the metal parts treater. The WCL may also, or additionally, be based on agent concentration in the air space above the containerized waste treatment residuals. Minimum required levels are typically 1 STEL (short-term exposure limit)—0.0001 mg/m3 for GB, 0.00001 mg/m3 for VX, and 0.003 mg/m3 for HD.