Divine Strake in Nevada: What were 'safety experiments:' 

In 1957-1958, the Atomic Energy Commission conducted a handful of plutonium dispersal experiments, also called 'safety experiments,' at the Nevada Test Site.  The purpose of the tests was to determine how far pure, unexploded plutonium might be scattered by accidents involving nuclear bombs.   A few safety experiments were even associated with a slight nuclear yield.  

The safety experiments were conducted at five locations on the Nellis Air Force Range and two locations (Area 3 and Area 11) on the Nevada Test Site.  The plutonium from all the safety experiments combined resulted in significant quantities of plutonium dispersed on the surface.  In 1970, the Atomic Energy Commission (A.E.C.) reported that the safety experiments contaminated about 250 sq. miles of the 1,350 sq. mile Nevada testing grounds, however the agency did not indicate the  quantities of contamination.  In 1990, a DOE report whittled that number down to 148 square miles and didn't include, however did mention, the contamination in Area 11 (which had plutonium levels that are 10,000 to 100,000 times above background levels).  Area 11 comprises a total of 26 square miles.   So, what about the remaining 76 square miles of plutonium-contaminated soil at the Nevada Test Site - have they been cleaned up since 1970?

Although the amount of plutonium-239 released into soils from the safety tests isn't known, the Department of Energy admitted in 1998 that four tons of plutonium (both pu239 and pu240) was released in the soil at the Nevada Test Site during four decades of atomic testing as bomb residue.  Compare this to the number given by the 1982 report of the United Nations Scientific Committee on the Effects of Atomic Radiation, which stated that between 1945 and 1980 global nuclear testing dispersed about 2.8 tons of plutonium-239 across the globe. 

The site of the Divine Strake blast in Area 16 is due west of two of the locations of the dispersal experiments (Areas 3 and 11).  The cloud from one safety experiment in Area 3, Coulomb B, drifted west over Area 16.  Coulomb B, which had a nuclear yield of 300 tons (one of the highest yields of any of the safety experiments), was one of three safety experiments part of the 1957 Operation Plumbob test series.   In 2005, the DOE published a map of the NTS that designated Area 16 as an area with high concentrations of plutonium.

Officials from the Department of Energy have conceded that plutonium from these safety tests was picked up by strong winds and scattered beyond the boundaries of the NTS, short for Nevada Test Site.  In 1997, a Nevada scientist found trace amounts of Plutonium-239, which he believed originated from the dispersal experiments, in the attics of homes in Las Vegas, St. George and other towns in Utah and Nevada.  Plutonium-239 was also detected by the EPA in other parts of Nevada and northern Utah.  Read Atomic 'Safety Tests' in 1950s Showered Utah With Plutonium .

This pure form of plutonium 239 is 1,000 times more potent than the dust- and debris-covered form that results from an atomic blast.  Only ten micrograms (a microscopic amount) of Plutonium-239, if inhaled, is an amount 'almost certain to induce cancer.'    

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