Anchorage Daily News (AK); Business; October 23, 1996
The U.S. Department of Energy is testing a technique to corral a leaking nuclear waste pond using technology pioneered in Erwin Long's back yard in the 1950's. In a cool solution to a hot problem, the government this year chose Long's company, Arctic Foundations Inc., to freeze the ground around a leaky pond of radioactive soil and sludge. At Oak Ridge National Laboratory in Tennessee, where the soil-freezing test will take place, ''some people say if anyone can do it, those Alaskans can,'' said program manager Elizabeth Phillips.
Arctic Foundations has been freezing soil under buildings, towers and airport runways from Gakona to Greenland for more than two decades. Why? To keep those structures from settling, heaving or jacking out of the ground.
Long's technology even keeps some of the above-ground sections of the trans-Alaska oil pipeline from sinking into the tundra.
With this $1.25 million demonstration project, the Anchorage-based company is applying cold-weather construction technology to a tricky hazardous waste problem and might produce a solution that could be used throughout the country, Phillips said.
The government is paying Arctic Foundations $1 million, but the company must kick in $250,000 toward the project, Phillips said.
The company, which employs seven to 14 people, depending on the workload, pulls in about a $1 million a year, Long said.
Here's the problem in Oak Ridge, one of the nation's nuclear test laboratories: In the shadow of a mothballed experimental reactor lies a buried rectangular pond, capped with asphalt. That pond received low-level radioactive waste and water during the reactor's operations between 1957 and 1961, Oak Ridge documents show.
Radioactive strontium 90 and cesium 137 lace the soil, rock and sludge that fills the pond. Whenever it rains, groundwater washes through the pond and radioactive water flows underground into a nearby stream, Phillips said.
Arctic Foundation's job is to freeze the soil around the pond, creating a 12-foot thick frozen fence that should keep the water from flowing through, Phillips said.
To do so, the company will insert into the ground a series of gas-filled pipes cooled in part by electrical refrigeration. This system is a variation on ground-freezing techniques Long has used in cold climates, he said.
Long, 75, started his career as the king of cold, cold ground more than four decades ago. As a young engineer at the U.S. Army Corps of Engineers, his bosses called on him when building foundations in permafrost or other waterlogged soils shifted, heaved and buckled, he said.
Permafrost -- as the name implies -- is soil that is permanently frozen. It lies under the surface, covered by a layer of soil that freezes and thaws, a seasonal cycle that ''can destroy foundations in a matter of seasons,'' according to a company brochure.
One permafrost building technique involves sinking piles into the frozen layer. But the heat from a building can conduct downward, melting the permafrost and causing the building to tilt or settle, Long said.
Another technique involves constructing a building on grade, using gravel and insulation under the structure to keep it from melting into the tundra.
Long's systems keep the soils frozen under both types of buildings.
Using steel pipes planted next to his Turnagain home, Long in 1956 developed a simple gas-filled tube that freezes soil without electricity or any outside energy source.
In 1964, the backyard tinkerer was awarded his first patent for the ''thermo probe'' soil freezer. Since then, he's been awarded eight other patents related to soil freezing, he said. Long started Arctic Foundations in 1973 and has been running it full time since he retired from the Army Corps in 1976.
The company's probes have been used to stabilize Bethel's runway, Nome's recreational center and oil company buildings at Prudhoe Bay, Long said.
Long also developed refrigerated piles, a technology that has been used throughout Alaska, from Kotzebue's hospital to the supports that hold portions of the trans-Alaska oil pipeline above ground.
The basic soil freezing system works this way:
A steel pipe filled with pressurized carbon dioxide gas or another refrigerant is inserted into the ground, with one end sticking out.
During the winter, the ground is warmer than the air, causing the gas to absorb heat from the soil, then ''boil'' and rise into the section of tube above the ground.
In the upper end of the pipe, which is exposed to the cold air, the gas condenses into a liquid, releasing its heat in the process. The liquid drips down the pipe wall and the cycle starts over.
The underground cold that has built up during the winter then lasts all summer, Long said.
In Tennessee, where the summers are long and the winters relatively warm, Long will use electrical refrigeration to supplement the cooling probes. The federal Environmental Protection Agency will monitor the pond for a year and conduct tests to see if the frozen barrier holds.
Oak Ridge, ''is dealing with this as highly experimental,'' Long said. But after spending some 40 years freezing deep dirt, Long concluded, ''we don't feel like it's that experimental. But we'll do it to satisfy you.''
Bruce Melzer, Daily News Reporter Staff
Copyright (c) 1996, Anchorage Daily News