SOUTH HEART, N.D. (AP) - Planners of a $1.4 billion coal gasification plant in southwestern North Dakota say it may turn uranium into an ash that could be used on roads for dust suppression.

Officials of Great Northern Power Development LP spoke Wednesday night at a public hearing that packed the South Heart school gymnasium. It was the first in a series of hearings to provide information on the project.

"With the buffer zone in there, we're looking at just under 5,000 acres," Great Northern Vice President Richard Voss said. "We're still just looking at potential expansion, but have to figure out the best way to do that."

Technical consultant Al Lukes said studies are under way on the use of uranium ash.

"The uranium forms from the process of decay in deep seams in the earth, and in our plant it will be produced into an ash that's a glassy substance," Lukes said. "It's a BB like material which cannot be inhaled unless broken down, and the danger of uranium is being inhaled."

Work is being done to ensure the glassy ash substance is safe and not broken down so it could be inhaled while on the roads, he said.

"Radon is present all around us and we all get our basements tested for it," Lukes said. "There's no indication radon would be a problem with this plant."

Lukes said carbon dioxide from the South Heart plant could be stored in the Williston Basin. Studies are under way on carbon sequestration proposals in North Dakota.

Great Northern is planning a synthetic natural gas plant and coal mine near South Heart, in western Stark County. The company has said it wants to begin construction in late 2009.

An affiliated company, Great Northern Properties LP, holds 3 billion tons of lignite reserves in western North Dakota. Both companies are based in Houston.

The plant's effect on water in the area was one of the major questions from residents at Wednesday night's hearing.

"We're using the best science available to see what wells are affected and how they will be," Voss said. "Great Northern will enter into agreements with each well owner to guarantee replacement of their water in quality and quantity. We are establishing contingency plans, looking at every well, and our intent is to work with every well owner affected within our buffer zone."