Aging Stores of Chemical Weapons May Pose Public Risk

WASHINGTON, DC, February 10, 2004 (ENS) - The U.S. Army should more aggressively monitor the condition of munitions containing the chemical agents sarin, VX, and mustard in storage at eight U.S. military sites to better document degradation, leaks, and corrosion, according to a new report from the National Academies' National Research Council.

The Army is storing more than three million chemical weapons with some 23,000 tons of nerve agents at the eight facilities until they can be destroyed. Under international treaty, the United States must destroy this stockpile of chemical weapons. The United States is one of over 154 governments that are Parties to the Chemical Weapons Convention, which prohibits the development, production, stockpiling, and use of chemical weapons.

Improved tracking of problems could allow better assessment of the risks posed by the chemical agents while they are stored and facilitate disposal operations for the aging stockpiles, according to the National Research Council committee that wrote the new advisory report.

"Because these munitions are leaking and degrading over time, they increase risk to the general public, the environment, and especially workers at the storage sites," said Peter Lederman, committee chair and retired professor of chemical engineering at the New Jersey Institute of Technology in Newark.

VX rockets are moved from a storage igloo to an onsite container for destruction at the Tooele Chemical Agent Disposal Facility in Utah. (Photo courtesy PMECW)

When leaking items are found, they are overpacked, that is they are placed inside another container and sealed, and returned to storage. Some leakers have been overpacked several times. Workers in protective clothing perform the overpacking procedure and also decontaminate any area that has been affected by a leak.

Hazards to workers may arise if an agent leaks, and explosives, called "energetics" stored in the "igloos" with the agents, ignite. But to date, workers have handled leaks without injury. For instance, on January 28, mustard agent vapor was detected in a storage igloo at Deseret Chemical Depot during routine monitoring operations. Crews in protective clothing entered the filtered igloo, and discovered four 155mm projectiles leaking vapor. The projectiles were overpacked into airtight containers for continued storage. There was no danger to the environment, the Army said.

On November 13, 2003 another potentially dangerous situation occurred, but was handled without incident. A piece of rocket debris momentarily ignited in a self-contained weapons processing room at the Army’s Anniston Chemical Agent Disposal Facility in Alabama causing a fire alarm to sound. Fire dampers were immediately closed and within a matter of moments, the fire burned itself out. The Army said there was no release of chemical agent and there was no danger to the work force or the public.

But the National Research Council committee said the Army should do more to watch for trends. "The Army should regularly monitor the stockpile to spot possible trends, such as an increased frequency of leaks, and to make corrections at the earliest possible time," said Lederman.

"The safe dismantlement and disposal of a chemical weapons arsenal is no easy matter," U.S. Assistant Secretary of State for Arms Control Stephen Rademaker told the First Review Conference of the Chemical Weapons Convention last April. "While the total costs of this undertaking in the United States are currently estimated at $24 billion, we remain steadfastly committed to the safe, environmentally sound, and verifiable destruction of our stockpile."

To date, 26 percent of the total agent stockpile has been destroyed and 39 percent of the munitions have been destroyed.

Of the eight sites, four are under construction, three are actively destroying their stockpiles, and the work of one, at Johnston Atoll in the Pacific Ocean, is complete.

The weapons are destroyed using high temperature incineration technology, which the Army emphasizes it has used safely for more than a decade. Robotic equipment disassembles the weapons and each component is treated in separate incinerators. Successful operations at the Army’s first weapons disposal facility, located on Johnston Island, have resulted in process and safety enhancements across the program.

Worker at the Tooele Chemical Agent Disposal Facility in Utah signals that his protective equipment is working correctly before entering a toxic area. (Photo courtesy PMECW)

The committee called on the Army to improve its program for acquiring and storing this data, and analyze it for trends in leak development and other problems.

A specific concern addressed in the report is the possibility that leaks may increase with temperature, and the panel recommended the Army consider monitoring to determine whether the rate of leaks is related to temperature.

Because the average outdoor temperature at different storage sites varies over time, it may affect the rate at which the agents degrade and also may damage container materials.

The commitee cited the current lack of knowledge about the risk of leakage due to degradation as another cause of concern.

What data is available indicates that most leaks occur in munitions containing sarin, while leaks in munitions holding VX and mustard agent have been comparatively rare. Because of this higher rate of leakage, sarin munitions have been monitored more closely.

While stabilizers were added to sarin and VX at the time of manufacture to retard decomposition, these stabilizers have degraded over time, the committee reports. The resulting acidic decomposition products may corrode metal containment vessels, leading to agent leakage, particularly for sarin.

"Agent degradation may be expected to accelerate at elevated temperatures and longer storage times," the committee warned. This could result in increased leakage rates before these munitions are scheduled for destruction.

"The ongoing degradation of these munitions is at present only a minor contributor to the risks from storage of these weapons," Lederman said. "But such degradation will continue, and the extent to which leaks and other anomalous conditions will happen is difficult to predict. The swift destruction of the munitions is ultimately the only effective way to reduce risks to the public."