Tag Archives: Manhattan Project

Atomic Snapshots: Trinitite

Trinitite is a mineral with a glass-like consistency that was formed by arkosic sand drawn up inside the fireball of the plutonium atom bomb tested at the Trinity site in New Mexico.

Trinitite sample
A fragment of trinitite found on display at the Harry S Truman Presidential Library.

Trinitite glass formed both as pancake fragments (like the crusted top of a crème brûlée) on the ground from the blast as well as formed into bead and dumbbell shapes that rained down in molten form when material was drawn into the fireball.

Trinity ground zero
Air photo of ground zero 28 hours after the Trinity Test. The dark material with radiating spikes is the trinitite glass layer. Most of this material was subsequently buried. (White Sands Missile Range)

Green trinitite, the most common, is theorized to contain blobs of melted iron and lead which are bits and pieces of the first atomic bomb and the support structure. Green trinitite

Red trinitite, found to the north of the test area, contains material in the glass from the copper wires that connected the bomb to instruments in the bunkers.

Trinitite
Trinitite found on the ground while at the Trinity Site Open House, White Sands Missile Range

Trinitite can still be found at the Trinity site (available for visits twice each year during the White Sands Missile Range Open House) although most of it was removed and buried by the U.S. government.

Since 1952, it has been illegal to take trinitite from the site. Prior to the ban, lots of the material was gathered for collectors, jewelry, and souvenirs. Trinitite from that era is still widely available for trade.

Trinitite is only mildly radioactive and considered safe to handle.

End of the Manhattan Engineering District

On August 15, 1947, the Manhattan Engineering District was formally abolished, although the Manhattan Project ceased to exist on December 31, 1946, with the handover to the U.S. Atomic Energy Commission effective January 1, 1947.

Manhattan Engineering District plaque located in Oak Ridge, TN

The Manhattan Engineering District was created August 13, 1942, and was initially headquartered at 270 Broadway, New York, which was the home to the North Atlantic Division of the U.S. Army Corps of Engineers. Much of the early activities, purchase, and storage of uranium occurred in New York City.

Tower 270 viewed east from Chambers Street with the Tweed Courthouse in the foreground.

The headquarters was eventually moved to Oak Ridge, TN. The project retained the Manhattan Project name, even though the “district” included the entire United States.

Hanford PFP Demolition Delayed


On Monday, October 31, 2016, after more than 20 years of planning, the demolition of what is considered Hanford’s most hazardous facility was delayed due to high winds. The Tri-City Herald reported that it should continue some time this week. 

“The Plutonium Finishing Plant, also known as PFP, represented the end of the line (the final procedure) associated with plutonium production at Hanford. PFP was also known as “Z-Plant” due to the fact that no further Hanford activity related to plutonium production would be done after the plutonium had been processed here. The plant began operations in 1949.”  (DOE Source)