AIKEN - Several environmental activists attended a public hearing to support the U.S. Energy Department's recommendation for plutonium disposal in glass matrices at Savannah River Site.

The Energy Department is looking at ways to dispose of 13 metric tons of surplus plutonium at a price tag of $300 million to $500 million if it uses the recommended process of a glass matrix.

Environmental impact studies and public input on the recommendation is under way by the Energy Department before a final decision is made in 2008. The project is expected to last until 2013.

"This is plutonium that is not in the form that it can be used for a weapon," said project director Allen Gunter. "We need to get it into a form so it can be disposed to Yucca Mountain. The preferred method is to put it into a glass matrix so it can be stored for thousands of years."

Under the proposed recommendation, the plutonium would go through a vitrification process, where it would be melted with lanthanide borosilicate glass, which means if the glass ever cracked, the plutonium could not leak out. This process would take place in the K Area of SRS.

The glass would then go to the Defense Waste Processing Facility and be placed in a canister and surrounded with high-level radioactive waste. The materials would be stored at SRS until Yucca Mountain in Nevada opens as a permanent storage facility.

Dr. Edwin Lyman, of the Union of Concerned Scientists in Washington, D.C., said that although he supported the immobilization process, he'd like to see the scope of the project expand to all plutonium waste in the country.

"This is a critical new mission at SRS, and we're an advocate for immobilization of plutonium," he said. "South Carolina is going to be stuck with this material for some time, and what this can do is put it in a more stable form to be shipped out of state expeditiously."

In the past five years, SRS has disposed of plutonium in a Mixed Oxide, or MOX, fuel project.

Those who prefer the MOX program over the immobilization said it keeps plutonium in a form that preserves the energy and the essence of its creation.

"We won't lose the energy content of the plutonium, and we can at least recover a portion of that investment," said Ernest Chaput, of the Economic Development Partnership. "Vitrification increases what needs to go to Yucca Mountain, and if it opened tomorrow, it is already fully subscribed."

The public can still submit comments or alternatives to the recommendations to the Energy Department until May 29. The Energy Department will publish all comments before next summer.