The Pueblo Chemical Depot (PCD) in Colorado is one of two sites that features U.S. stockpile of chemical weapons that need to be destroyed. The PCD features about 2,600 tons of mustard-including agent. The PCD also features a pilot plant, the Pueblo Chemical Agent Destruction Pilot Plant (PCAPP), which has been set up to destroy the agent and munition bodies using novel processes. The chemical neutralization or hydrolysis of the mustard agent produces a Schedule 2 compound called thiodiglycol (TDG) that must be destroyed. The PCAPP uses a combined water recovery system (WRS) and brine reduction system (BRS) to destroy TDG and make the water used in the chemical neutralization well water again. Since the PCAPP is using a novel process, the program executive officer for the Assembled Chemical Weapons Alternatives (ACWA) program asked the National Research Council (NRC) to initiate a study to review the PCAPP WRS-BRS that was already installed at PCAPP. 5 months into the study in October, 2012, the NRC was asked to also review the Biotreatment area (BTA). The Committee on Review of Biotreatment, Water Recovery, and Brine Reduction Systems for the Pueblo Chemical Agent Destruction Pilot Plant was thus tasked with evaluating the operability, life-expectancy, working quality, results of Biotreatment studies carried out prior to 1999 and 1999-2004, and the current design, systemization approached, and planned operation conditions for the Biotreatment process. Review of Biotreatment, Water Recovery, and Brine Reduction Systems for the Pueblo Chemical Agent Destruction Pilot Plant is the result of the committee's investigation. The report includes diagrams of the Biotreatment area, the BRS, and WRS; a table of materials of construction, the various recommendations made by the committee; and more.

Assessment of Supercritical Water Oxidation System Testing for the Blue Grass Chemical Agent Destruction Pilot Plant reviews and evaluates the results of the tests conducted on one of the SCWO units to be provided to Blue Grass Chemical Agent Destruction Pilot Plant. The Army Element, Assembled Chemical Weapons Alternatives (ACWA) is responsible for managing the conduct of destruction operations for the remaining 10 percent of the nation's chemical agent stockpile, stored at the Blue Grass Army Depot (Kentucky) and the Pueblo Chemical Depot (Colorado). Facilities to destroy the agents and their associated munitions are currently being constructed at these sites. The Blue Grass Chemical Agent Destruction Pilot Plant (BGCAPP) will destroy chemical agent and some associated energetic materials by a process of chemical neutralization known as hydrolysis. The resulting chemical waste stream is known as hydrolysate. Among the first-of-a-kind equipment to be installed at BGCAPP are three supercritical water oxidation (SCWO) reactor systems. These particular hydrolysate feeds present unique non-agent-related challenges to subsequent processing via SCWO due to their caustic nature and issues of salt management.This report provides recommendations on SCWO systemization testing inclusive of durability testing and discusses systemization testing objectives and concepts.

Because of concerns about incineration, the Department of Defense plans to use alternative means to destroy the chemical agent stockpiles at the Pueblo and Blue Grass facilities. The DOD contracted with Bechtel Parsons to design and operate pilot plants for this purpose. As part of the NRC efforts to assist the DOD with its chemical demilitarization efforts, the Department requested a review and assessment of the Bechtel designs for both plants. An earlier report presented an assessment of the Pueblo design. This report provides a review of the Blue Grass Chemical Agent Destruction Pilot Plant based on review of data and information about the initial design and some intermediate design data. Among other topics, the report presents technical risk assessment issues, an analysis of delivery and disassembly operations and of agent destruction core processes, and an examination of waste treatment.

In 1993, the United States signed the Chemical Weapons Convention (CWC), an international treaty outlawing the production, stockpiling, and use of chemical weapons. The chemical weapons stockpiles at five of the U.S. chemical weapons storage sites have now been destroyed. At those sites, the munitions were robotically opened and the chemical agent was removed, collected, and incinerated. One of the remaining sites with chemical weapons stockpiles is the Blue Grass Army Depot near Richmond, Kentucky. In this case, caustic hydrolysis will be used to destroy the agents and energetics, resulting in a secondary waste stream known as hydrolysate. Review Criteria for Successful Treatment of Hydrolysate at the Blue Grass Chemical Agent Destruction Pilot Plant develops criteria for successfully treating the hydrolysate, identifies systemization data that should factor into the criteria/decision process, suggests potential modifications to suggested treatment that would allow continued onsite processing, and assesses waste disposal procedures. This study further examines the possibility of delay or failure of the existing technology and examines possible alternatives to onsite treatment.

The U.S. Army Program Manager for Assembled Chemical Weapons Alternatives (PMACWA) is charged with disposing of chemical weapons as stored at two sites: Pueblo, Colorado, and Blue Grass, Kentucky. In accordance with congressional mandates, technologies other than incineration are to be used if they are as safe and as cost effective. The weapons are to be disposed of in compliance with the Chemical Weapons Convention. Although an element of the U.S. Army, the PMACWA is responsible to the Assistant Secretary of Defense for Acquisitions, Technology, and Logistics for completing this mission. This book deals with the expected significant quantities of secondary wastes that will be generated during operations of the facilities and their closure. While there are only estimates for the waste quantities that will be generated, they provide a good basis for planning and developing alternatives for waste disposal while the plants are still in the design phase. Establishing efficient disposal options for the secondary wastes can enable more timely and cost-effective operation and closure of the facilities.

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.

In 1996, Congress enacted directing the Department of Defense to assess and demonstrate technology alternatives to incineration for destruction of the chemical weapons stored at Pueblo Chemical and Blue Grass Army Depots. Since then, the National Research Council (NRC) has been carrying out evaluations of candidate technologies including reviews of engineering design studies and demonstration testing. Most recently, the NRC was asked by the Army to evaluate designs for pilot plants at Pueblo and Blue Grass. These pilot plants would use chemical neutralization for destroying the chemical agent and the energetics in the munitions stockpiles of these two depots. This report provides the interim assessment of the Pueblo Chemical Agent Destruction Pilot Plant (PCAPP) to permit adjustment of any significant problems as soon as possible. The report presents an analysis of the issues about the current PCAPP design and a series of findings and recommendations about ways to reduce concerns with involve the public more heavily in the process.