BACKGROUND

Since the 1963 ban prohibiting aboveground nuclear testing, the United States has conducted 828 underground nuclear tests in the desert environs of the Nevada Test Site-the primary location for U.S. nuclear weapons experimentation. In addition, 12 underground nuclear tests were conducted outside the boundaries of the NTS at 8 sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. By comparison with the Nevada Test Site, these offsite test areas are generally more accessible to the public.

Three-dimensional map of Shoal ground zero (orange) and the boundary of the area withdrawn from public use (blue line).		Map of Nevada showing location of Shoal in proximity to cities and roadways.

The inactive Shoal test site is one of these offsite locations. Situated along the crest of the Sand Springs Range in western Nevada, this site is 30 miles southeast of the town of Fallon . This site occupies 4 square miles (10.4 square kilometers) and lies adjacent to public lands. Conducted jointly by the U.S. Department of Defense and U.S. Atomic Energy Commission (predecessor to DOE), Project Shoal was detonated 367 meters (1 204 feet) below the land surface on October 26, 1963 . The test produced an announced yield of 12.5 kilotons and was designed to enhance seismic detection of underground nuclear tests in active earthquake areas.

Cross section through the Sand Springs Range showing valleys on both sides. (Red line indicates land surface.)

DRI researchers have studied the local and regional hydrology affecting the Shoal site as well as migration of contaminants. These studies have focused on developing a capability to predict, with a high degree of confidence, where contaminants are transported, how rapidly transport is occurring, and present levels of radioactivity.

Regional map showing area surrounding the Shoal underground nuclear test site.

Regional hydrologic investigations of the Shoal test site were hampered initially due to lack of groundwater data. Subsequent groundwater studies, combined with studies on radionuclide chemistry to predict migration, focused on building groundwater contaminant transport models as well as obtaining additional groundwater data. Through the contaminant transport models, greater understanding of the distribution of radionuclides in time and space was gained.