Chemical burn

Transcription

The Blue Grass Chemical Agent-Destruction Pilot Plant is being built to safely destroy 523 tons of chemical agent in rockets and artillery projectiles stored at the Blue Grass Army Depot in Kentucky. The U.S. Department of Defense has selected neutralization, followed by Supercritical Water Oxidation, as the method to destroy the Blue Grass chemical weapon stockpile. Under the charter of the Defense Department Assembled Chemical Weapons Alternatives, preservation of public health, safety, and the environment is paramount. Therefore, the plant is being constructed, tested, and operated and closed following federal and state regulations and codes. Today, the munitions are safely stored in earthen-covered bunkers known as igloos, under the responsibility of the Blue Grass Chemical Activity and the Blue Grass Army Depot. Before we begin our journey observing the destruction process, let's take a minute to familiarize ourselves with a stockpile of chemical munitions. The stockpile consists of three types of munitions filled with three different chemical agents. M-55 rockets with nerve agent Sarin, or GB and VX, 155-mm projectiles with VX and mustard, or H (a blistering agent), and eight inch projectiles filled with GB. There are several steps involved in the safe and efficient destruction of the chemical weapons stockpile, including: removal or separation of energetics, which contain propellants and explosives; removal of the chemical agents; neutralization of the chemical agents; neutralization of the energetics; thermal treatment of the rocket and projectile metal parts. Additionally, the byproduct from neutralization of the chemical agents and energetics is caustic waste water known as hydrolysate, which will require secondary treatment using supercritical water oxidation. The Blue Grass Chemical Agent- Destruction Pilot Plant consists of three primary facilities, and several support structures on a nineteen-acre site. Now, let's observe firsthand how processing stockpiled munitions occurs in the plant. Storage and processing takes place in the Chemical Limited Area, which provides safety and security for the munitions and the workforce. The two main buildings that neutralize the chemical agent and energetics are in this area. The control and support building - the brains of the plant - houses the control room, and integrated control system that workers use to operate the plant. The munitions demilitarization building is where the chemical munitions are disassembled using robots, and the energetics and agent neutralized through an automated process. And the supercritical water oxidation processing building, located outside the Chemical Limited Area, houses reactors where a blend of agent hydrolysate and energetic hydrolysate are subjected to very high temperature and pressures in a secondary treatment process to destroy the hydrolysates' organic content. Before the destruction process begins, munitions from the stockpile are transported to the Container Handling Building - part of the Munitions Demilitarization Building - via the Enhanced On-site Container transport system, or EONC. EONC's are designed to resist impacts, punctures, crushing and fires. They also prevent release of chemical agent into the environment in the unlikely event a munition should develop a leak during transport. At the igloos, EONC's are loaded with chemical munitions, the door secured, and the seal verified before transport to the Container Handling Building. The Container Handling Building provides a safe and secure storage area for the EONC's for a ready supply of munitions to support continuous plant operations. The EONC's are monitored to ensure that no munitions have leaked, and then unloaded in the unpack area, which is monitored as well. EONC's containing munitions that have developed leaks are moved through an air lock to an explosive containment vestibule inside the Munitions Demilitarization Building, for unpacking by workers wearing enhanced, safe, personal protective equipment. Processing begins as the munitions are unloaded and placed on feed conveyors to start the automated destruction process, safely behind the Munitions Demilitarization Building's reinforced concrete walls, which are more than 2 feet thick. Rockets and projectiles go through the same neutralization process, but the method of disassembly differs for each munitions. Rockets travel through blast gates into one of the two explosive containment vestibules, and begin processing at the rocket cutting machine. The rocket cutting machine cuts the shipping and firing tubes surrounding the rocket, removes the shipping and firing tube from the warhead, and then separates the rocket into two major components: the warhead agent field section, and the rocket motor propellant-filled section. The motor and other non-agent contaminated parts are transported to the Motor Packing Room for monitoring and storage before being shipped off-site for disposal. Conveyors move the rocket warhead through several blast gates into the Explosive Containment Room. There, at the rocket shear machine, two holes are punched through the bottom of the warhead and vent nozzles through the top. Gravity drains the agent through the bottom and wash water is sprayed from the vent nozzles to rinse out the remaining agent. The drained agent is pumped to the agent holding tank in the Agent Neutralization System Room for agent destruction. The warhead then moves to the shear station where it is cut into pieces which are transferred to the energetics batch hydrolyzer for additional processing. The energetics batch hydrolyzer neutralizes the energetics and any residual agent by hydrolysis. Hydrolysis occurs as the rocket parts and pieces are mixed with water and caustic, then heated at 240 degrees Fahrenheit and aggressively mixed for three hours. Upon completing the batch processing time, the remaining processed parts and pieces are transferred to a shaker conveyor that drains any residual liquid, while tranferring the pieces to the metal parts treater for further processing. The remaining liquid, known as energetic hydrolysate is transferred to the Energetic Neutralization Room, for additional processing. Projectiles are disassembled in a different manner. Projectiles are unloaded from the EONC and unpalletized in the unpack area. The projectiles are manually loaded into projectile-handling system feed trays and transferred to the Munitions Washout System Room for processing. Projectiles of all agent types follow the same process in the Munitions Washout System Room. A robot transfers the projectiles to a burst or detection sensor, to verify bursters are not present. The projectiles then move to the Cavity Access Machine for agent draining. The projectile nose is inserted into a fixture and clamped into place. A ram driven into the burster cavity collapses the burster well and allows the agent to drain. High pressure water then flushes the agent liquids and residues from the munition body. Drained agent and wash water are transferred to the Agent Neutralization System Room for processing. The empty projectile bodies are transferred to the metal parts treater for final decontamination. The metal parts treater thermally decontaminates metal pieces and projectile bodies by heating them to at least 1000 degrees Fahrenheit for a minimum of 15 minutes. The army has shown this minimum temperature and time adequately decontaminates metal parts and contaminated secondary wastes. The Agent Neutralization System Room stores agent collected within the agent storage tanks from the rocket shear machine and the projectile cavity access machine, and rinse water from the rocket and projectile high pressure washouts. Two agent neutralization reactors ensure complete agent neutralization for each type of agent by mixing the agent with hot water and caustic for approximately two hours to two-and-a- half hours. After the specified processing time has elapsed, the reactors are cooled, and the resulting hydrolysate is sampled and analyzed. If required, additional processing in the reactor is provided until agent destruction is verified. After agent destruction is verified, the reactor contents are pumped to the appropriate hydrolysate storage tanks to await processing in the Supercritical Water Oxidation Building. Energetic Hydrolysate, created by processing rocket warheads in the energetic batch hydrolyzer units, is transferred and stored in tanks in the Energetic Neutralization System Room. Three energetics neutralization reactors process energetics, hydrolysate and condensate from the off-gas treatment of energetics batch hydrolyzers to neutralize the energetics and agent. After neutralization is verified, the reactor contents are cooled and pumped to the energetics hydrolysate storage tank. Before the energetics hydrolysate undergoes the supercritical water oxidation process, it receives further treatment. Supercritical water oxidation - a secondary treatment process - blends energetics hydrolysate, agent hydrolysate, and other additives together in the supercritical water oxidation systems reactors. There, they are combined with water under high temperature and pressure conditions, fuel and air to yield products consisting of carbon dioxide, water and salts. Sufficient time at temperature is provided in the reactor to ensure destruction of organic compounds to meet permit requirements. The liquid affluent is monitored to ensure that it can be collected and reprocessed if necessary. The liquid affluent is sent to the water recovery system to recover and reuse about seventy percent of the water. The remaining concentrated salt solution, also called brine, is transported to a licensed treatment, storage and disposal facility for final disposition. The Munitions Demilitarization Building is equipped with an agent filtration area with a negative air pressure system called cascading ventilation. Fresh air is continually drawn into the building and can only return to the atmosphere after passing through a series of carbon filter units that scrub the air as it passes through the multiple carbon banks in each filter unit. An agent monitoring system continuously monitors between the carbon banks and the exhaust point as an added layer of environmental protection. Together the army and the surrounding community, in conjunction with the Bechtel Parsons Blue Grass team, are working in a committed partnership to meet the highest standards of safety, quality and performance for the safe destruction of the Blue Grass chemical weapons stockpile. More information about the Blue Grass Chemical Agent-Destruction Pilot Plant project is available at the Blue Grass Chemical Stockpile Outreach Office. Or by visiting the project's social media and web sites.