The compound had been routinely accumulated in air filters that service some of the gloveboxes at the 200 Area of the facility. An analysis performed in July 2010 discovered that the substance, which theretofore believed to be benign, is highly explosive ammonium nitrate. Following that discovery, processing activity in two areas of the facility has been suspended, shutting down parts the only U.S. facility that can produce plutonium "triggers" for nuclear weapons.

In the September 10, 2010 memo DNFSB reported that the ammonium nitrate was created in a reaction of ammonia vapors from cleaning products used in one of the restrooms with nitric acid vapors from the gloveboxes. The fact that the plutonium processing lines and the bathroom have a common ventilation system is a serious safety design flaw. For years, personnel were finding this dangerous explosive compound on filters without attempting to find out what it was.