When you think of nuclear test sites, remote Pacific islands and desert wastelands come to mind. Not many people think of Hattiesburg, MIssissippi -- but the United States carried out two nuclear tests in a little town just outside that city in 1964, in an operation that went by the reassuring-to-no-one moniker Project Dribble. No one saw any mushroom clouds, though, because the two nukes they tested were detonated underground, in a 3,000-foot-deep shaft drilled into a reservoir of ancient salt called the Tatum Salt Dome (left over from the Mesozoic era, when that part of the state was covered by sea water). Those were the early days of the Nuclear Test Ban, and we were trying to figure out if other nations could cheat by doing underground tests that could fool seismographs -- so we did a few of our own. Here's a bit of Shatner-narrated footage of the tests:
An area five miles downwind and two miles upwind from the test site was evacuated. Inconvenienced residents were paid $10 per adult and $5 per child for their trouble, and many came back to find collapsed shelves in their kitchens, cracks in their ceilings, and wells that had gone dry. People a few miles from the site who weren't evacuated said that they felt three separate shocks, during which the soil rose and fell like ocean waves. Two miles from the blast, the shockwave shook pecans from the pecan trees. In Hattiesburg, thirty miles away, tall buildings swayed for several minutes, and people noticed rivers and streams running black from churned-up silt. All this from a bomb one-third the strength of the one dropped on Hiroshima twenty years earlier. When a crew lowered a television camera and some equipment into the underground crater after the explosion, it measured more than a hundred feet in diameter. Three months later, the air in the hole it made was still four hundred degrees.
The government reimbursed people for damage to their homes, and to ease fears about radioactive drinking water, they built a pipeline to serve people who lived near the test site. Over the years, there have been scattered claims of higher-than-average rates of illness in the area, and at least one person was paid by the government to resolve unspecified health claims, but there hasn't been any great public outcry. A lot of younger people in Lamar County, Mississippi have never heard of Project Dribble -- but if they were to venture past the gates erected by the Department of Energy to the test site, they would find a stone monument and a brass plaque warning future generations not to drill in the area. (Let's hope that plaque can last 10,000 years or so, when people -- if there are any -- will really need it.)
Oh, and as for the test results, we figured out that you could indeed fool a seismograph by performing nuclear tests in underground caves, which significantly muffle shockwaves. Thanks to Project Dribble, though, we pioneered new ways to catch nuclear cheaters.