Project Rio Blanco was an underground nuclear test that took place on May 17, 1973 in

Rio Blanco County, Colorado Rio Blanco County () is a county located in the U.S. state of Colorado. As of the 2020 United States census, 2020 census, the population was 6,529. The county seat is Meeker, Colorado, Meeker. The name of the county is the Spanish language, Spa ...

, approximately 36 miles (58 km) northwest of

Rifle A rifle is a long gun, long-barreled firearm designed for accurate shooting and higher stopping power, with a gun barrel, barrel that has a helical or spiralling pattern of grooves (rifling) cut into the bore wall. In keeping with their focus o ...

. Three 33-kiloton nuclear devices were detonated nearly simultaneously in a single emplacement well at depths of below ground level. The tests were conducted in fine-grain, low-permeability sandstone lenses at the base of the Fort Union Formation and the upper portion of the

Mesaverde Formation History The Mesaverde Formation was first described by William Henry Holmes, W.H.Holmes in 1877 during the Hayden Survey. Holmes described the formation in the northern San Juan Basin as consisting of three units, which were a "Lower Escarpment ...

. This was the third and final natural-gas-reservoir stimulation test in the Plowshare program, which was designed to develop peaceful uses for nuclear explosives. The two previous tests were Project Gasbuggy in New Mexico and Project Rulison in Colorado. The

United States Atomic Energy Commission The United States Atomic Energy Commission (AEC) was an agency of the United States government established after World War II by the U.S. Congress to foster and control the peacetime development of atomic science and technology. President Harry ...

conducted the test in partnership with CER Geonuclear Corporation and Continental Oil Company. A placard, erected in 1976, now marks the site where the test was conducted. The site is accessible via a dirt road, Rio Blanco County Route 29.

Devices

As the creation of tritium was of greatest concern, the three devices used were specially designed to reduce

tritium Tritium () or hydrogen-3 (symbol T or H) is a rare and radioactive isotope of hydrogen with a half-life of ~12.33 years. The tritium nucleus (t, sometimes called a ''triton'') contains one proton and two neutrons, whereas the nucleus of the ...

production, creating less than tritium each, primarily from the medium surrounding the devices. To reduce emplacement costs, the devices were very narrow in diameter, less than wide.

References

{{US nuclear tests Explosions in 1973 May 1973 in the United States American nuclear weapons testing American nuclear test sites Rio Blanco Rio Blanco County, Colorado Rio Blanco 1973 in Colorado Rio Blanco Rio Blanco