Operation Plowshare - Plowshare Testing

Plowshare Testing

One of the first plowshare nuclear blast cratering proposals that came close to being carried out was Project Chariot, which would have used several hydrogen bombs to create an artificial harbor at Cape Thompson, Alaska. It was never carried out due to concerns for the native populations and the fact that there was little potential use for the harbor to justify its risk and expense. A number of proof-of-concept cratering blasts were conducted; including the Buggy shot of 5 1-Kt-devices for a channel/trench in Area 21 and the largest being 104 kiloton (435 terajoule) on July 6, 1962 at the north end of Yucca Flats, within the Atomic Energy Commission's Nevada Test Site (NTS) in southern Nevada. The shot, "Sedan", displaced more than 12 million short tons (11 teragrams) of soil and resulted in a radioactive cloud that rose to an altitude of 12,000 ft (3.7 km). The radioactive dust plume headed northeast and then east towards the Mississippi River.

The first PNE blast was Project Gnome, conducted on December 10, 1961 in a salt bed 24 mi (39 km) southeast of Carlsbad, New Mexico. The explosion released 3.1 kilotons (13 TJ) of energy yield at a depth of 361 meters (1,184 ft) which resulted in the formation of a 170 ft (52 m) diameter, 80 ft (24 m) high cavity. The test had many objectives. The most public of these involved the generation of steam which could then be used to generate electricity. Another objective was the production of useful radioisotopes and their recovery. Another experiment involved neutron time-of-flight physics. A fourth experiment involved geophysical studies based upon the timed seismic source. Only the last objective was considered a complete success. The blast unintentionally vented radioactive steam while the press watched. The partly developed Project Coach detonation experiment that was to follow adjacent to the Gnome test was then canceled.

Over the next 11 years 26 more nuclear explosion tests were conducted under the U.S. PNE program. Funding quietly ended in 1977. Costs for the program have been estimated at more than (US) $770 million.