Plan A took 15 years to build, cost $489 million - and failed. Plan B would have taken until 2010 and cost up to $1 billion to complete.
Now, Savannah River Site officials have moved to Plan C in their efforts to treat 34 million gallons of radioactive waste.
The new plan will use an existing SRS plant to treat and store the waste for decades. Site officials say the method will be cheaper and quicker than previous proposals.
"We are dissecting the problem," Greg Rudy, the U.S. Department of Energy's manager at SRS, said during a recent public meeting. "We want a multipronged approach to start the treatment programs earlier and reduce the risks earlier."
But some observers say the site is merely choosing a new path to the same result.
"They have not changed their approach of simply going from one failure to another," said Arjun Makhijani, the president of the Institute for Energy and Environmental Research in Tacoma Park, Md.
"The Energy Department has done this before. They've gone cheap, with shortsighted solutions that turned into long-term cleanup problems."
The agency's proposal might be new, but it is an attempt to solve an old conundrum: how to treat 34 million gallons of "salt waste" at SRS.
The salt waste makes up the bulk of the highly radioactive liquid wastes in the site's 49 underground waste tanks. It contains high levels of cesium and smaller amounts of other radioactive elements such as plutonium.
Site officials have sought to remove those highly radioactive constituents from the rest of the waste, allowing the waste to be treated in separate "streams."
The cesium would go to the site's Defense Waste Processing Facility to be turned into a solid, radioactive glass suitable for long-term burial.
The remaining waste, much less radioactive, would go to the site's Saltstone plant, where it would be mixed with sand, slag, fly ash and concrete and solidified into blocks of a cementlike grout.
The radioactive blocks would remain in vaults at Saltstone for hundreds of years.
Separating the waste into two streams, however, has proved problematic.
The Energy Department first built the in-tank precipitation facility to do the work. Scientists and engineers spent 15 years and $489 million building the plant.
But in January 1998, shortly after it opened, the plant was declared inoperable because operators could not prevent flammable, carcinogenic benzene from building up inside its tanks.
In the years since, the Energy Department has searched for other ways to strip cesium from the salt waste.
After an extensive search, the agency selected a technology called "solvent extraction" as the basis for another new plant to replace the in-tank facility.
The new plant, which was to use a liquid solvent to remove the cesium, was expected to cost up to $1 billion. The sticker price was one reason, Energy Department officials said, that they have chosen to pursue a third option.
"We want to make sure our strategy is a cost-effective one," said Terrel Spears, the director of salt processing for the Energy Department's high-level waste division at SRS. "We're confident we can save substantial sums of money."
THE NEW PLAN would send some of the salt waste to Saltstone as is, to be turned into grout, Mr. Spears said. More waste would go to Saltstone after chemicals were used to remove plutonium, Mr. Spears said.
Although the waste would contain more cesium than normally is sent to Saltstone, the plant would be able to handle it, officials say.
"Saltstone is not going to accept any waste that would not meet its waste-acceptance criteria," said Soni Blanco, a program engineer for the Energy Department's salt-processing division at SRS.
If much of the waste could be sent directly to Saltstone, Mr. Spears said, it would reduce the size of the solvent-extraction plant needed to handle the most troublesome salt waste.
Under the new plan, the plant could be built at 10 to 20 percent of the size that was originally planned, he said.
Some hurdles remain. Tests must be completed to determine whether Saltstone can handle the waste as expected, Mr. Spears said.
"We hope to walk before we run," he said. "We're challenging our contractor during the next couple of years to develop and mature the low-curie salt capability."
Site officials also must resolve regulatory issues. The salt waste is classified as high-level waste but must be reclassified if it is to be sent directly to Saltstone.
That issue is one reason the site's Citizens Advisory Board raised concerns about the proposal in January.
The board expressed concern that the high-level-waste determination would hold up the project. If salt-waste treatment is delayed further, it could hinder efforts to treat SRS waste and close the site's waste tanks before deadlines agreed on with the site's environmental regulators, the board said.
"The SRS Citizens Advisory Board again confirms its position that the closure schedule must be met, including start-up of a full-scale salt-processing facility by 2010 and the closures of the high-level waste tanks as scheduled," the board wrote.
EVEN IF SRS officials can treat and store salt waste at Saltstone, it doesn't mean they should, Dr. Makhijani said.
"This will turn South Carolina into a de facto nuclear-waste dump, in the worst way," he said.
But a site supporter said he had no qualms about using Saltstone to treat the waste.
"We were well-aware that when this study was made public that there would be some resistance to it, because we've always said that we were going to treat all of our high-level waste and remove it from the site," said Mal McKibben, the executive director of the Aiken-based pro-nuclear group Citizens for Nuclear Technology Awareness.
"That resistance is the bad news. The good news is that Greg Rudy is 100 percent correct when he says that this approach would allow us to save a lot of money and get it done a lot faster.
"That's the pluses and minuses right there."
"We want to make sure our strategy is a cost-effective one. We're confident we can save substantial sums of money." - Terrel Spears, director of salt processing for the Energy Department's high-level waste division at SRS
Reach Brandon Haddock at (706) 823-3409 or firstname.lastname@example.org.