LIST 36

13 Nuclear Tests That Spread Radiation into Civilian Areas

From September 1961 to September 1992, the United States military conducted 824 nuclear tests. Of these, 433 released radioactive material into the area surrounding the immediate detonation site. In 52 such incidents, the atomic particles drifted outside of the entire testing area (usually the Nevada Test Range) and into civilian areas.

1

Antler

Date: September 15, 1961 (first known test in which radiation leaked offsite)
Location: Nevada Test Site
Bomb yield: 2.6 kilotons
Length of release: unknown
Farthest location radiation detected: “21.1 miles northeast of the junction of Highway 6 and Highway 25 (Nevada)”
Most radiation detected: 28 picocuries @ Diablo, Nevada

2

Gnome

Date: December 10, 1961
Location: Carlsbad, New Mexico
Bomb yield: 3.0 kilotons
Length of release: “Large flow” for 30 minutes; “small flow” until the following day
Farthest location radiation detected: Roswell, New Mexico
Most radiation detected: 160 picocuries @ IMCC Mine, New Mexico

3

Pampas

Date: March 1, 1962
Location: Nevada Test Site
Bomb yield: 9.5 kilotons
Length of release: 20 minutes
Farthest location radiation detected: Sand Springs Valley, Nevada
Most radiation detected: 1,700 picocuries @ Penoyer, Nevada

4

Platte

Date: April 14, 1962
Location: Nevada Test Site
Bomb yield: 1.85 kilotons
Length of release: not specified
Farthest location radiation detected: “28.1 miles northeast of Currant, Nevada”
Most radiation detected: 34,000 picocuries @ Queen City Summit, Nevada

5

Sedan

Date: July 6, 1962
Location: Nevada Test Site
Bomb yield: 104 kilotons
Length of release: not specified
Farthest location radiation detected: near McGill, Nevada
Most radiation detected: 13,000 picocuries @ Diablo, Nevada

6

Johnnie Boy

Date: July 11, 1962
Location: Nevada Test Site
Bomb yield: 500 tons
Length of release: not specified
Farthest location radiation detected: 11 miles northeast of Lockes, Nevada
Most radiation detected: 23,000 picocuries @ Twin Springs Ranch, Nevada

7

Small Boy

Date: July 14, 1962
Location: Nevada Test Site
Bomb yield: “low”
Length of release: not specified
Farthest location radiation detected: “seven miles south of Parowan, Utah, on Highway 143”
Most radiation detected: 140,000 picocuries @ Elko, Nevada

8

Bandicoot

Date: October 19, 1962
Location: Nevada Test Site
Bomb yield: 12.5 kilotons
Length of release: five minutes
Farthest location radiation detected: 14.5 miles south of Shoshone, California
Most radiation detected: 52,000 picocuries @ Death Valley Junction, California

9

Double Tracks

This test was not technically a nuclear explosion. Rather, it was more along the lines of what we now call a “dirty bomb.” The US and British militaries wanted to study dispersal of radioactive particles, so they did the logical thing: Out in the open, they used conventional explosives to scatter plutonium to the four winds.

Date: May 15, 1963
Location: Nellis Air Force Range (adjacent to Las Vegas)
Bomb yield: N/A
Length of release: N/A
Farthest location radiation detected: not specified
Most radiation detected: “Alpha activity detected on air samplers at Beatty, Nevada and Scotty's Junction, Nevada”

10

Baneberry

Date: December 18, 1970
Location: Nevada Test Site
Bomb yield: 10 kilotons
Length of release: 24 hours
Farthest location radiation detected: Austin, Nevada, although, in a seeming contradiction, the military reported: “parts of the [nuclear] cloud moved over Nevada, Utah, and Wyoming; another fraction moved towards California.”
Most radiation detected: 3,400 picocuries @ Stone Cabin Ranch, Nevada

11

Misty Rain

Date: April 6, 1985
Location: Nevada Test Site
Bomb yield: under 20 kilotons
Length of release: “controlled ventilation” occurred from two and a half to four days later
Farthest location radiation detected: Reed Ranch Road, Nevada; Rachel, Nevada
Most radiation detected: “No radiation intensities above background levels were detected.” (Then how was the radiation detected in Reed Ranch Road and Rachel?)

12

Glencoe

Date: March 22, 1986
Location: Nevada Test Site
Bomb yield: 29 kilotons
Length of release: unspecified length on March 27
Farthest location radiation detected: Lathrop Wells, Nevada.
Most radiation detected: not specified

13

Mighty Oak

Date: April 10, 1986 (last known test in which radiation leaked offsite)
Location: Nevada Test Site
Bomb yield: under 20 kilotons
Length of release: From April 22 to May 19, eight “controlled ventilations” were performed
Farthest location radiation detected: “No radiation intensities above background were detected.”
Most radiation detected: 430±15 picocuries @ Medlins Ranch, Nevada