Metrics For Successful Supercritical Water Oxidation System Operation At The Blue Grass Chemical Agent Destruction Pilot Plant

The Department of Defense, through the Assembled Chemical Weapons Alternatives program, is currently in the process of constructing two full-scale pilot plants at the Pueblo Chemical Depot in Colorado and the Blue Grass Army Depot in Kentucky to destroy the last two remaining inventories of chemical weapons in the U.S. stockpile. These two storage sites together account for about 10 percent of the original U.S. chemical agent stockpile that is in the process of being destroyed in accordance with the international Chemical Weapons Convention treaty. Unlike their predecessors, these facilities will use neutralization technologies to destroy agents contained within rockets, projectiles, and mortar rounds, requiring the use of specially designed equipment. As part of its focus on safe operation of the planned facilities, the Program Manager for Assembled Chemical Weapons Alternatives asked the National Research Council (NRC) to conduct a study to offer guidance on the application of process safety metrics at the Pueblo Chemical Depot and Blue Grass Army Depot. Process safety is a disciplined framework for managing the integrity of operating systems, processes and personnel handling hazardous substances, and operations by applying good design principles, engineering, and operating practices. Process Safety Metrics at the Blue Grass and Pueblo Chemical Agent Destruction Pilot Plants discusses the use of leading and lagging process safety metrics that could provide feedback on the effectiveness of controls to mitigate risks and minimize consequences of potential incidents. The book makes several recommendations that will facilitate the development and application of process safety metrics at both sites.

January 2012 saw the completion of the U.S. Army's Chemical Materials Agency's (CMA's) task to destroy 90 percent of the nation's stockpile of chemical weapons. CMA completed destruction of the chemical agents and associated weapons deployed overseas, which were transported to Johnston Atoll, southwest of Hawaii, and demilitarized there. The remaining 10 percent of the nation's chemical weapons stockpile is stored at two continental U.S. depots, in Lexington, Kentucky, and Pueblo, Colorado. Their destruction has been assigned to a separate U.S. Army organization, the Assembled Chemical Weapons Alternatives (ACWA) Element. ACWA is currently constructing the last two chemical weapons disposal facilities, the Pueblo and Blue Grass Chemical Agent Destruction Pilot Plants (denoted PCAPP and BGCAPP), with weapons destruction activities scheduled to start in 2015 and 2020, respectively. ACWA is charged with destroying the mustard agent stockpile at Pueblo and the nerve and mustard agent stockpile at Blue Grass without using the multiple incinerators and furnaces used at the five CMA demilitarization plants that dealt with assembled chemical weapons - munitions containing both chemical agents and explosive/propulsive components. The two ACWA demilitarization facilities are congressionally mandated to employ noncombustion-based chemical neutralization processes to destroy chemical agents. In order to safely operate its disposal plants, CMA developed methods and procedures to monitor chemical agent contamination of both secondary waste materials and plant structural components. ACWA currently plans to adopt these methods and procedures for use at these facilities. The Assessment of Agent Monitoring Strategies for the Blue Grass and Pueblo Chemical Agent Destruction Pilot Plants report also develops and describes a half-dozen scenarios involving prospective ACWA secondary waste characterization, process equipment maintenance and changeover activities, and closure agent decontamination challenges, where direct, real-time agent contamination measurements on surfaces or in porous bulk materials might allow more efficient and possibly safer operations if suitable analytical technology is available and affordable.

One of the last two sites with chemical munitions and chemical materiel is the Pueblo Chemical Depot in Pueblo, Colorado. The stockpile at this location consists of about 800,000 projectiles and mortars, all of which are filled with the chemical agent mustard. Under the direction of the Assembled Chemical Weapons Alternative Program (ACWA), the Army has constructed the Pueblo Chemical Agent Destruction Pilot Plant (PCAPP) to destroy these munitions. The primary technology to be used to destroy the mustard agent at PCAPP is hydrolysis, resulting in a secondary waste stream referred to as hydrolysate. PCAPP features a process that will be used to treat the hydrolysate and the thiodiglycol - a breakdown product of mustard - contained within. The process is a biotreatment technology that uses what are known as immobilized cell bioreactors. After biodegradation, the effluent flows to a brine reduction system, producing a solidified filter cake that is intended to be sent offsite to a permitted hazardous waste disposal facility. Water recovered from the brine reduction system is intended to be recycled back through the plant, thereby reducing the amount of water that is withdrawn from groundwater. Although biotreatment of toxic chemicals, brine reduction, and water recovery are established technologies, never before have these technologies been combined to treat mustard hydrolysate. At the request of the U.S. Army, Review Criteria for Successful Treatment of Hydrolysate at the Pueblo Chemical Agent Destruction Pilot Plant reviews the criteria for successfully treating the hydrolysate. This report provides information on the composition of the hydrolysate and describes the PCAPP processes for treating it; discusses stakeholder concerns; reviews regulatory considerations at the federal, state, and local levels; discusses Department of Transportation regulations and identifies risks associated with the offsite shipment of hydrolysate; establishes criteria for successfully treating the hydrolysate and identifies systemization data that should factor into the criteria and decision process for offsite transport and disposal of the hydrolysate; and discusses failure risks and contingency options as well as the downstream impacts of a decision to ship hydrolysate offsite.

"One of the last two sites with chemical munitions and chemical materiel is the Pueblo Chemical Depot in Pueblo, Colorado. The stockpile at this location consists of about 800,000 projectiles and mortars, all of which are filled with the chemical agent mustard. Under the direction of the Assembled Chemical Weapons Alternative Program (ACWA), the Army has constructed the Pueblo Chemical Agent Destruction Pilot Plant (PCAPP) to destroy these munitions. The primary technology to be used to destroy the mustard agent at PCAPP is hydrolysis, resulting in a secondary waste stream referred to as hydrolysate. PCAPP features a process that will be used to treat the hydrolysate and the thiodiglycol - a breakdown product of mustard - contained within. The process is a biotreatment technology that uses what are known as immobilized cell bioreactors. After biodegradation, the effluent flows to a brine reduction system, producing a solidified filter cake that is intended to be sent offsite to a permitted hazardous waste disposal facility. Water recovered from the brine reduction system is intended to be recycled back through the plant, thereby reducing the amount of water that is withdrawn from groundwater. Although biotreatment of toxic chemicals, brine reduction, and water recovery are established technologies, never before have these technologies been combined to treat mustard hydrolysate. At the request of the U.S. Army, Review Criteria for Successful Treatment of Hydrolysate at the Pueblo Chemical Agent Destruction Pilot Plant reviews the criteria for successfully treating the hydrolysate. This report provides information on the composition of the hydrolysate and describes the PCAPP processes for treating it; discusses stakeholder concerns; reviews regulatory considerations at the federal, state, and local levels; discusses Department of Transportation regulations and identifies risks associated with the offsite shipment of hydrolysate; establishes criteria for successfully treating the hydrolysate and identifies systemization data that should factor into the criteria and decision process for offsite transport and disposal of the hydrolysate; and discusses failure risks and contingency options as well as the downstream impacts of a decision to ship hydrolysate offsite."--Publisher's description.

The U.S. Army has asked the National Research Council (NRC) to evaluate whether supercritical water oxidation (SCWO) is an effective and appropriate means of eliminating hazardous or toxic organic constituents in VX hydrolysate for ultimate disposition. The NRC was not asked to conduct an in-depth analysis of the entire integrated VX bulk agent destruction and disposal process for the Newport Chemical Agent Disposal Facility. As the facility design is being finalized (March 1999-April 2000), the NRC will probably be asked to assess all aspects of the facility design, including monitoring, containment, process control, and redundancy, as well as the quantitative risk assessment (QRA). This report outlines the elements of the proposed neutralization/SCWO technology, evaluates the results of ongoing SCWO tests, and makes recommendations concerning aspects of the technology that require further development. The scope of this evaluation did not include evaluations of other potential technologies or management options for the treatment of VX hydrolysate.