Project Sedan, On-Site Radiological Safety Report
Abstract
The Sedan Experiment, part of the Atomic Energy Commission's Plowshare Program to develop peaceful uses for nuclear explosives, consisted of detonating a thermonuclear device of about 100 kiloton yield 635 feet underground in the alluvial flats at the northern part of the Nevada Test Site. The device was a relatively clean thermonuclear device in which fission contributed less than 30 per cent of the total yield. It was emplaced in a 36 inch diameter cased hole that was back filled with sand. Detonation occurred at 10 a.m. pacific daylight time on July 6, 1962. Some of the smaller earth particles formed a dust cloud which rose to a height of about 12,000 feet above the desert floor, somewhat higher than expected. The detonation formed a crater measuring about 1,200 feet across and 320 feet deep. About 7.5 million cubic yards of earth and rock were removed. The lip of the crater varied in height from about 20 to almost 100 feet. The predicted crater diameter was 1,200 to 1,400 feet and the depth from about 170 to 300 feet. As expected, most of the radioactivity produced by the explosion was trapped underground. A precise determination of the percentage of escaping radioactivity cannot be obtained from the available preliminary data, but this data shows that there was no major deviation from the prediction that about 95 per cent of the radioactivity would be trapped in the ground. The cloud, carrying dust and the small fraction of radioactivity which was not trapped underground or deposited close to the crater, drifted north at a speed of about 12 miles per hour. The heavier fallout was confined to within about two miles upwind and crosswind, and four miles downwind of ground zero, in line predictions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 23, 1962
- Accession Number
- ADA436354