Neutralizing Nuclear Waste

March 22, 1993|By Ted Shelsby | Ted Shelsby,Staff Writer

Robert E. Prince seems like an easygoing guy, except when you ask about his days as a Navy submariner.

"I could tell you about that, but I would have to kill you," the nuclear engineer jokes, referring to the time in the 1970s when he served aboard the USS Narwhal, an attack submarine later featured in the Tom Clancy techno-thriller, "The Hunt for Red October."

"We were in the Atlantic." And that's as much as the 45-year-old Naval Academy graduate will say.

Though cloaked in secrecy, his military service steered Mr. Prince onto a course that has led to his current job as president and chief executive of GTS Duratek Inc. and his involvement with another remnant of the Cold War -- cleaning up tons of radioactive waste left from the production of nuclear bombs.

But Mr. Prince is not nearly as bashful when discussing his current job.

He'll tell anyone who will listen about the Columbia company's recent "major milestone" in converting low-level nuclear waste into glass for safe storage for thousands, if not millions, of years.

He'll talk about the opportunities ahead for Duratek.

He'll talk about the Duratek process, developed in conjunction with Catholic University of America and the Department of Energy, and how it makes use of ingredients already in the nuclear waste to cut the processing cost.

Duratek is still celebrating its success last month when, for the first time, it made glass from low-level nuclear waste from holding ponds at the government's closed nuclear weapons plant at Fernald, Ohio, a suburb of Cincinnati.

Actually the big moment was anticlimactic, Mr. Prince says. "There were so many steps along the way that we knew it would work."

Trying to explain a rather complex subject in simple terms, Mr. Prince says the glass-making process works like this:

Contaminated soil from a waste storage site is washed with water, and 80 percent of the soil is returned to the ground.

The water is then cleaned by passing it through an ion exchange and recycled or used over and over again in the soil cleaning process.

The remaining contaminated soil, which contains silica used in making glass, is mixed with radioactive sludge from the Fernald storage pits. The sludge also contains magnesium fluorides and calcium carbonates, which Mr. Prince calls "great fluxing agents used in making glass."

In an oversimplification of the process, he says, the contaminated soil and sludge are mixed in something "like a giant Mixmaster blender" yielding a substance that resembles chocolate fudge mix.

The mix is poured into an oven -- a machine called a Duramelter -- and baked at 2,000 degrees Fahrenheit. When it's done, out come nuggets of glass that resemble flattened, shiny black marbles about three-quarters of an inch in diameter.

"The radioactive waste is trapped in the glass, like the green color in a beer bottle," Mr. Prince says. "You can break the bottle, but the green stays in the glass. It's the same with our process; the radioactive waste is trapped inside the glass."

The glass is still radioactive, but in this form, it can't leach into the soil or ground water, he says. Low-level radioactive particles are not usually dangerous unless ingested or breathed.

"We start out with radioactive contaminated soil and water and radioactive sludge and we make it into clean water, clean soil and glass," he says.

Duratek developed its glass-making process under a $3.4 million contract from the Department of Energy's Office of Technology Development. The original Duramelter was designed to produce 22 pounds of glass a day and is tiny compared to future models.

The company is testing a 220-pounds-a-day machine and is working on a 660-pounds-a-day machine that it plans to have operating at Fernald this summer.

If things go well, the government may order four 100-tons-a-day melters next year at a cost of about $1.2 billion. They would be used for the next 10 years to clean up the pools of waste at Fernald, one of more than 100 government waste storage sites around the country. Duratek plans to bid for the work.

There is a lot of waste to clean up. The Department of Energy estimates that if the all of the country's low-level nuclear waste were piled on a football field, it would be a 6-mile-high radioactive tower.

And cleaning it up is a high priority for the federal government, which plans to spend more than $30 million in the next five years and between $200 billion and $600 billion over the next 30 years to do the job.

Mr. Prince says Duratek is bidding on a potential $10 million contract to clean up waste at the federal Savannah River Site nuclear weapons complex at Aiken, S.C. The project would take two years.

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