Project Shoal

On August 5th, 1963, the treaty banning atmospheric nuclear testing was signed by the U.S. and Russia. However it didn’t halt the testing of nuclear testing underground.

The Project Shoal site near Fallon became one of two test sites in Nevada used for such testing.

An Atomic Energy Commission office opened in Fallon. A Dr. Robert Frosch, working out of that office, said the area was chosen for its closeness to the epicenter of 1954 Dixie Valley-Fairview Peak earthquakes. The aftershocks of those quakes were so extensive they were still being recorded in 1963.

He told the ‘Fallon Eagle-Standard,’ “The primary purpose is to obtain seismic signs from a nuclear explosion in an area where natural earthquakes occur, in order that we can compare the seismic signatures from the two sources occurring in the same area and thus having the same characteristics.”

He added it was imperative to find ways to discover underground Soviet tests and to distinguish them from earthquakes.

On October 26th, 1963, an atomic bomb was detonated underground in the mountains about 20 miles southeast of Fallon. The 12.5-kiloton nuclear device was about 80 percent as powerful as the one dropped on Hiroshima in World War II.

The government spent more than $5 million on the project. Before the detonation, four miles of land surrounding ground zero was withdrawn from public use by the BLM at the request of the AEC.

At GZ, a head frame was constructed and a shaft was drilled 1,211 feet deep. From the bottom of the shaft, a 1,000-foot tunnel was drilled through the solid granite rock.

There also were buildings, machines and vehicles there to measure, document and calibrate the blast forces, a first aid trailer, a mobile radio-assay lab for counting alpha and beta activity, personnel decontamination trailer, a weather trailer and a mobile laundry trailer for decontaminating clothing.  Along with this were 18 remote gamma detectors.

Precautions such as off-site surveillance from five to 50 miles from ground zero began in July 1963 to find a baseline of radioactive contamination and continued on the day of the test and afterward. There was no reported rise in radiation at any point.

On the day of the test, the public was invited to watch from about four and a half miles away on State Route 839, which is known locally as Nevada Scheelite Mine Road. A parking area had been made along the highway and next to the road leading to GZ for observers and for those driving on the highway who had to be stopped jus’ before the blast occurred.

At six, the morning of the detonation, the Federal Aviation Administration began broadcasting warnings every half hour for aircraft to avoid the airspace to 12,000 feet and 50 nautical miles southeast. The bomb was detonated at 10 a.m., and about four seconds later, a loud roar filled the air and a dust cloud 1,000 feet tall began to rise over desert.

A magnesium flare marked the moment the blast went off, but it was a couple of seconds later when those in the parking lot were jarred by a severe ground shock. A seismograph reported a reading of about 4.7 on the Richter scale.

The earth bulged, but no crater was formed. Instead a shaft, nearly 170 feet in diameter and 460 feet high was created, with rock fractures extending out in all directions for hundreds of feet and several tons of radioactive rubble believed to contain two kilograms of unburned plutonium-239 with a half-life expectancy of 24,000 years filling it.

Although no radiation leaked into the atmosphere during the test, the ‘Fallon Eagle–Standard’ reported December 17th, 1963, drillers had found temperatures of 600 degrees and radiation that peaked at 40 Roentgen per hour. A final radiological safety survey, conducted in 1964, found all radiation levels were not above natural background levels.

The area was cleaned by scraping the surface and mixing the contaminated soil with clean soil and burying that soil under several feet on contaminated earth.  Decommissioned in 1964, it would another six years before the land was once again returned to the BLM and open to the public.

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