Frozen Soil Could Stop Spread of OR Waste

Knoxville News-Sentinel (TN); Section A; April 12, 1997

OAK RIDGE - Nuclear winter?

A test project on the Department of Energy's Oak Ridge reservation will freeze the ground in an effort to stem the spread of radioactive contamination. Arctic Foundations Inc., a company based in Alaska, has a $1 million contract to conduct the demonstration over the next couple of years. Preliminary work will begin later this month.

The project will create a barrier of frozen soil around a pond adjacent to the old Homogeneous Reactor Experiment. The test reactor operated in the late 1950s and '60s, and the pond contains nuclear wastes as a result of cooling waters discharged there.

Arctic Foundations uses a piped system of liquid carbon dioxide to freeze the soil and to maintain a 12-foot barrier that's supposed to prevent migration of pollutants.

``It's a fantastic technology,'' said DOE spokesman Steven Wyatt, who noted the soil will remain frozen for months even if the power fails.

Similar systems have been tested or used commercially elsewhere, but Elizabeth Phillips, DOE's project manager, said, ``This marks the first time that soil-freezing technology has been applied to control the spread of contamination at a site . . . with radioactivity.''__

Wyatt said a few months will be spent preparing the site and installing the necessary instrumentation, followed by a four-month period of freezing the soil. After that, there will be an eight-month experiment to monitor the barrier and assess results.__

``There is an option to extend the contract,'' Wyatt said.

Strontium-90 is the radioactive substance of most concern at the site, but there also are quantities of cesium-137.

Wyatt said it's too early to say if the technology will be used at other sites on the government's Oak Ridge reservation.

Frank Munger, News-Sentinel, Oak Ridge Bureau