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Radioactive Site Set for Excavation After Testing

Posted on: Wednesday, 19 October 2005, 18:00 CDT

By FRANK MUNGER, munger@knews.com

OAK RIDGE -- Workers will take samples from a troublesome hot spot next month in hopes of excavating the radioactive site -- smack dab in the middle of Oak Ridge National Laboratory -- next summer.

Bechtel Jacobs Co. plans to remove an empty 4,000-gallon waste tank and 200 cubic yards of highly contaminated soil from an area associated with the lab's early nuclear operations. Bechtel Jacobs is the U.S. Department of Energy's environmental manager in Oak Ridge.

Officials said they hope the cleanup will eliminate an environmental hazard that's been under study for more than a decade.

The project is sometimes referred to as Corehole 8. That's a reference to a test well drilled years ago that identified an underground plume of radioactive materials in the groundwater not far from the lab's cafeteria.

An attempt to remove the old tank in 2001 was called off after workers encountered unexpectedly high radiation fields during the digging.

John Owsley, the state's environmental oversight chief in Oak Ridge, said the area contains a number of radioactive elements, including plutonium, americium, curium, uranium, cesium and strontium.

The fact that nuclear waste is in contact with the groundwater in the middle of the ORNL complex is unacceptable, he said.

"The state's position is that the material should be in a geologic repository," Owsley said.

Some of the excavated materials will be transported to New Mexico for disposal at the Waste Isolation Pilot Plant.

The underground tank at ORNL was used decades ago to hold nuclear fuel leftover from reactor tests. The fuel mix was drained in the 1980s and put into cans for storage in the adjacent Building 3019- A.

According to a report by the Defense Nuclear Facilities Safety Board, "The contaminated soil resulted from leakage from a damaged joint in feed piping to the tank."

During the aborted cleanup effort four years ago, radiation was measured at levels as high as 20 rads per hour, board staffers reported. They said safety controls are being developed for the upcoming sampling program to limit the radioactivity of materials brought to the surface at any one time.

Owsley said DOE, as part of the Federal Facilities Agreement in Oak Ridge, is required to submit plans in January 2006 that will outline the cleanup activities and disposal of nuclear wastes.

"We expect them to begin excavation in May," the state official said. "We've been working on this for quite some time."

Although the location and extent of the contamination is a concern, Owsley said the situation is stable at present.

"The contaminated soil was covered in such a way that it didn't continue to leach into the environment," he said.

Dennis Hill, a spokesman for Bechtel Jacobs, said workers plan to sample soils around the tank in early October to better characterize what radioactive isotopes are present and their concentrations.

Those samples will help determine where the excavated wastes will be disposed, Hill said.

The so-called transuranic wastes, long-lived radioactive materials such as plutonium and americium, will be sent to WIPP, a deep-underground waste repository. The radioactive materials categorized as low-level waste will be transported to the nuclear landfill on DOE's Oak Ridge reservation.

Senior writer Frank Munger may be reached at 865-342-6329.

Source: News Sentinel

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