Light Gas Supports Heavy Mission

ammunition inspectors carefully lift the lid to the single round container (SRC), as the team leader reads detailed instructions aloud to ensure every step is properly performed. The team meticulously executes each required action, resulting in a successful test that validates the serviceability of the SRC. “The helium test is a vital part of our ability to quickly contain a leaking chemical munition,” said Jeffrey K. Angel, surveillance ammunition inspector for the Blue Grass Chemical Activity (BGCA). “Our quarterly tests ensure we have an SRC ready for use at all times in the rare event that a leaker occurs,” he said. “A successful helium test lets us know that the SRC will contain the agent when we place the leaking round into it. We call this process overpacking.” BGCA, located at Blue Grass Army Depot, Kentucky, stores more than 101,000 chemical filled munitions in 45 storage buildings called igloos. These include M55 rockets, 155 mm projectiles and rocket warheads. The chemical weapons at the depot were received as far back as 1944, and consist of the blister agent mustard (H) and nerve agents sarin (GB) and VX. Most munitions are stored without incident, however there are rare occasions when a munition will leak a vapor or liquid in storage. When this occurs, the leaking munition must be isolated and placed in an SRC to contain the leak, then moved to an igloo dedicated to storage of overpacked rounds. This helps to ensure the safety of the workers, community and environment. Each SRC must be tested to ensure no vapor or liquid from the munition can escape. But why test it with helium? “The helium atom is very small and lighter than air,” said John F. Trosper, chief quality assurance specialist. “GB, VX, and H molecules are all very large and heavier than air. If a helium atom cannot escape from an SRC we are very confident that molecules of toxic chemical munitions cannot escape either.” The test begins with inspecting the exterior and interior surfaces of the SRC for dents, cracks, gouges, rust and other irregularities. The butyl rubber O-ring is also analyzed for serviceability. If all is well, the ammunition inspectors record the SRC’s serial number, install the test O-ring and pressurize the test container using a helium dispenser. The container must be sealed within the time programmed into the dispenser for each SRC configuration, usually four to nine minutes. This helps to ensure an accurate reading. Once the lid is bolted back onto the SRC, the workers cover the container with a large plastic bag, tape the bag to get a good seal and insert the nozzle of the testing unit, the Leakhunter Plus 8066 leak detector. “The Leakhunter Plus is a high caliber piece of equipment that is commonly used across many industries,” said Angel. “It detects several different gas groups, including gas group one which includes helium. We expose the Leakhunter to helium prior to the test to be sure it is reading properly.” If the results are high after 15 seconds, then helium is leaking and a second test is performed. If the second test fails, the O-ring is replaced and the test is repeated. If an additional leak test failure occurs, the container is rejected. “We do not have many rejected SRCs,” said Angel. “If one does fail multiple tests, we take it out of rotation and call the Chemical Materials Activity for disposition instructions. Many times they will leave it here. We paint it blue and use it as a training tool for the crews to practice conducting overpack operations.” The helium test is a small but important part of BGCA’s mission to oversee the safe and secure storage of the chemical weapons stockpile. “I have a high degree of confidence in this test,” said Angel. “It is one way we work to ensure the safety of workers, the public and environment when a leaker occurs.” BGCA is committed to the safe and secure storage of the chemical weapons until the stockpile is destroyed at the Blue Grass Chemical Agent-Destruction Pilot Plant.

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