Feds, state close historic nuclear blast site

By Mary Manning

Wednesday, Aug. 5, 2009 | 4:53 p.m.

Part of the Nevada Test Site that hosted nuclear blasts in the past has been closed to avoid a costly cleanup of contaminated soils.

During the height of the Cold War, 100 above-ground nuclear weapons experiments were conducted in remote desert areas at the Test Site, 65 miles northwest of Las Vegas.

The Test Site covers an area larger than the state of Rhode Island and the federal government conducted nuclear weapons experiments above and below ground from 1951 until 1992.

Between May 25, 1952 and July 24, 1957, four nuclear explosions, including a test codenamed Fox, burst into the air from metal towers built at the T-4 site in Area 4 at the Test Site. Fox was conducted on May 25, 1952 and packed a nuclear punch equal to 11,000 tons of TNT.

After each blast, workers removed some metal debris and contaminated soils from the site. However, contaminated soils, tower remnants, a bunker and a soil berm, metal and concrete debris remained at the site in the northeastern section of the Test Site.

For more than 10 years, the U.S. Department of Energy, National Nuclear Security Administration's Nevada Site Office and the Nevada Division of Environmental Protection discussed how much cleanup would occur at these above-ground nuclear locations. The National Nuclear Security Administration is the nuclear weapons manager for the Energy Department.

The state approved plans to close this site on June 24.

The decision is expected to save taxpayers millions of dollars, said Kevin Cabble, acting soils federal sub-project director.

First, the Nevada Site Office designed an investigation into what remained, and how far hazardous and radioactive materials, such as lead, plutonium and cesium, had spread. Once the state Division of Environmental Protection approved, soil samples were collected and lead plates and batteries were removed.

Once environmental officials knew what and how much contaminated materials were at the site, state and federal officials considered current and future land use, potential risks to current and future workers and costs for removing or leaving the contamination and taking it to an appropriate disposal site.

After the evaluations, officials decided that the best method for protecting the environment and the public from this site was to close the area, including restrictions on future access to the land.

Administrative actions and physical controls will place formal land use restrictions on the contaminated site, workers will post warning signs and repair existing fencing around the contaminated area to limit future exposure to workers.

As part of the federal-state agreement, an annual inspection of the site will be conducted as part of a long-term monitoring effort.