WANMEC is made possible by Washington Physicians for Social Responsibility
With support and additional funding from INND and Toxipedia.org.
Support this project by donating to WPSR today.
Project Gnome was the first test in Operation Plowshare, a program to study and develop alternative, peacetime uses of nuclear devices. The main objective of the experiment was to see if the heat of a nuclear explosion could be harnessed to produce steam that could be used to generate electricity. Based on earlier underground detonations at the Nevada Test Site, scientists believed that roughly a third of the energy from the explosion was deposited in the melt rock at temperatures above 2,000 degrees F. They hoped that a nuclear detonation in a salt bed might cause heat to be stored long enough to be able to be recovered. Scientists wondered if the detonation itself could create steam that could beused to drive a steam or hot gas turbine coupled with an electric generator.
Other objectives included exploring the feasibility of recovering radioisotopes for scientific and industrial applications. Radioisotopes had become more widely used in scientific experiments, medical diagnosis, agriculture, and industrial production. One of the overall goals of the Plowshare program was to find new ways for manufacturing and recovering isotopes. During previous underground nuclear tests, large amounts of radionuclides had been entrapped in the molten rock formed by the explosion. Unfortunately the recovery of the radionuclides was difficult once the rock resolidifies.
Creating a test site
The area chosen for the test was a bed of rock salt in New Mexico near the town of Carlsbad. The salt bed was 225 million years old and covered by layers of clay and sandstone. A 1,216 foot shaft was drilled into the salt layer and a 1,115 foot long tunnel was made at the end of the shaft. The nuclear device was constructed at the end of the tunnel. A U-Shaped bend in the tunnel was built to form a seal when the nuclear device was detonated. Additional ventilation shafts were drilled down vertically into the chamber to introduce water and recover the superheated stream that would be produced by the high internal temperatures.
When President Kennedy authorized the experiment he described it as an "example of this country's desire to turn the power of the atom to man's welfare rather than his destruction." He invited observers from the countries of the United Nations, as well as representatives from the press and the scientific community. Over 400 observers were on hand for the event. On December 10, 1961 at noon, the device was detonated creating a 3.1 kiloton explosion. The blast left a chamber 170 feet in diameter and 80 feet high.
Leaked Radiation
Project Gnome had been planned as a contaminated explosion so the access tunnel had been plugged prior to the explosion. It unfortunately did not fully seal it in. Two to three minutes after the detonation, a cloud of steam appeared at the top of the shaft. Gray smoke, steam and radioactivity were emitting from the shaft opening. Radioactive materials vented into the atmosphere about 340 meters southwest of ground zero. Ten minutes after the detonation, large amounts of steam was escaping from the shaft, cracks in the surface layers, and through ventilation lines.
Over the next 40 minutes the flow rate increased as large quantities of steam escaped. The highest measured onsite gamma intensity was 1 R/h. This intensity was recorded 1,300 meters northwest of the shaft opening, seven hours after the detonation. A cloud formed and drifted northwest from the site. An hour after detonation a reading of 1.4 R/h was detected five miles away along Highway 128. This was the highest off site reading recorded. Although the amount of gas leaking began to decrease after 40 minutes, it continued until the next day. A few days later leaked radiation was recorded as far away as Kansas.
The surface radioactivity resulting from the escape of steam decayed rapidly. On the following day, a small flow of steam was still detectable. Underground recovery operations began six days after the detonation. These operations were delayed because levels of radiation at the shaft opening were as high as 5 R/h. When workers reentered that cavity on May 17, 1962, they found temperatures around 140 degrees Fahrenheit but only small amounts of residual radiation. The radiation released by the blast discolored salt of the inner walls turning them various shades of blue, green, and violet.
Aftermath
The AEC did not consider the test a success. The loss of the initial product of the explosion was seen as a failure. The failure of Project Gnome lead to a second test planned at the same location to be canceled. There are two small plaques above the test area today. One marks the chamber as a test spot. The other forbids drilling. Cattle are allowed to graze around the surface area. Eight miles away, and part of the same salt bed, is the long term nuclear storage facility, the Waste Isolation Pilot Plant.
References
Sanders, Ralph. Project Plowshare, the Development of the Peaceful Uses of Nuclear Explosions. Washington: Public Affairs, 1962
http://www.wipp.energy.gov/science/ug_lab/gnome/gnome.htm
Labels:
Example
Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
Aliquam fermentum vestibulum est. Sed quis tortor.
