After over three decades of effort, the United States has destroyed the last of its chemical weapon stockpile that once consisted of 30,000 tonnes of deadly chemical agents in explosive munitions and storage containers.
One of the unfortunate legacies of the Cold War is the tens of thousands of tonnes of nerve gas, blistering agents, and other chemical stockpiles that were amassed by the United States and the Soviet Union as a deterrent against either side using such horrors on the battlefield.
Since chemical weapons aren't very practical and are dangerous to store, the US Congress mandated in 1986, even before the fall of the Berlin Wall, that the destruction of American stockpiles should begin as soon as possible. The big problem was what to do with this inventory of death? It's much easier to create chemical weapons than to destroy them, so the only established method at that time was to dump them in deep sea areas.
Developing new technologies, the work began in 1990 on Johnston Atoll, an isolated, uninhabited island chain in the Pacific south of Hawaii, followed by six more sites in Alabama, Arkansas, Indiana, Maryland, Oregon, and Utah. It was only completed on July 7, 2023 at the Blue Grass Army Depot, Kentucky, when the final sarin-nerve-agent-filled M55 rocket was destroyed. This was the last of the stockpile that had been declared to the Organisation for the Prohibition of Chemical Weapons in the Hague under the Chemical Weapons Convention international arms control treaty that the United States ratified in 1997.
Originally, the destruction of the stockpile relied on high-temperature furnaces that broke down the agent's molecules into its base elements. After public concerns, incineration was abandoned in favor of two new methods.
One was neutraliation, where munitions were dismantled by robotic handlers and the chemical agents poured out. These agents were then mixed vigorously with hot water and sodium hydroxide to destroy or neutralize them.
The second was static detonation, which was used when the agent had solidified in part and stuck to the interior of the munition. Instead of dismantling the weapon, it was fed into an armored, high-temperature agent, which detonated the explosive in the munition, freeing up the agent to be destroyed by the heat. The same detonation process was used on the emptied munitions to decontaminate the scrap.
With the last US chemical weapon now history, contractor team Bechtel Parsons Blue Grass is concentrating its efforts on dismantling the contaminated disposal plant in Kentucky.
"We have a national security imperative and moral obligation to work toward eliminating the threat posed by weapons of mass destruction," said Under Secretary of Defense for Acquisition and Sustainment Dr William A. LaPlante. "This is the first time an international body has verified destruction of an entire category of declared weapons of mass destruction – reinforcing the United States' commitment to creating a world free of chemical weapons."
Source: US Department of Defense
