Disposal of more than a million tons of hazardous material is a monumental job. Here’s how Fluor is filling some 7,000 containers, each weighing more than 20,000 pounds.
The control room at
Empty containers weighing
When the Cold War cooled in 1989, a major battle still loomed for the U.S. Department of Energy. The government had to dispose of millions of tons of hazardous waste material.
Originally known as the Feed Materials Production Center, the Fernald Closure Project is located 18 miles upstream of Cincinnati. Today, the bucolic appearance of the facility belies what has lurked just below the surface for many years. Beginning in 1952, the plant produced 500 million pounds of high-purity uranium metal for the nation's defense programs during its 37-year run. Left behind were 31 million pounds of nuclear product, 2.5 billion pounds of lowlevel radioactive hazardous and mixed waste, and 2.5 million cubic yards of contaminated soil and debris.
After 25 years at the site, Dennis Carr, who's in charge of operations in the storage areas known as Silos 1 and 2, is beginning to see some light at the end of the tunnel. "We've just delivered the first of the final shipments. We're projected to have the silo material finished early in 2006," says Carr. He works for Fluor (Aliso Viejo, Calif.), the lead contractor responsible for this part of the project, which has managed the cleanup since 1992.
Carr surveys the constantly changing scene from a window in his construction-trailer office where stacks of photographs compete for space with volumes of reports and rolls of engineering plans. If placed in one continuous line of gondola cars, enough hazardous waste material has all ready been removed from the site (and disposed of in Utah) to create a train that would stretch 68 miles. Nearly one million tons of uranium and thorium processing wastes have been hauled away.
What needs to be done
This project is like eating the proverbial elephant: it's possible if you do it in small bites. Carr explains, in layman's terms, how they handled the hazardous material in the 28-foot-deep silos. First step was to "mine out" uranium wastes. The contaminated material contains radium and thorium radionuclides. This mining was done hydraulically. "We created a number of pumping systems to fluidize the material and retrieve the waste that had been packed into the silos for nearly 50 years," says Carr. "It was then moved to holding tanks inside the specially designed and built remediation building nearby. Now, the waste is being transformed into a grout-like substance using Portland cement and fly ash before it's packaged for transport."
Now that the waste material has been safely removed to the remediation facility, much of the construction required to move those final 8,900 cubic yards of material exists only in photographs. Like virtually everything at Fernald, if it hasn't been cut into small pieces, recycled, buried in on-site disposal cells or shipped out, it will be, soon. More than 230 of the 255 buildings and structures that were once the Feed Materials Production Center have been decontaminated and demolished.
How it's handled
The final product from Silos 1 and 2 is shipped to a facility in Andrews, Texas. It's 70 to 83 weight-percent inert material. "Each container, when loaded with stabilized material," says Carr, "weighs about 20,500 pounds so we get only two on a flatbed trailer."
The Department of Energy has classified the material from the silos, called K-65 Residues, as uranium byproduct. The material handling process for K-65 is virtually all automated. The white, innocuous-looking shipping containers are constructed of half-inch-thick cylindrical carbon steel. Each is 76 inches in diameter and 80 inches tall with a volume of 208 cubic feet. Empty containers weigh about 2,000 pounds and are moved with bridge cranes onto specially designed rail carts to travel through the filling process.
Inside the sealed building, the entire filling operation is monitored by numerous cameras giving engineers in the control room multiple views of each step in the process.
Jack Hughes, a process engineer, monitors the material handling activity from the safety of the control room, which is located in a building adjacent to the filling building. "We have three filling stations," he says, eyes fixed to the processing activity being simulated on a monitor in front of him. He points, "Two of these lines are in operation while the third is down for maintenance. We run 24/7 here."
Behind Hughes, images flicker on a bank of television monitors. On one, a bridge crane lifts a cylindrical cover and positions it over a filled cylinder. A half dozen engineers in the control room monitor various aspects of the movement.
Another screen gives a bird's-eye-view of protective-suited figures walking around the sealed cylindrical package making visual inspections and confirming what their instrumentation is telling them.
"The waste forms a low-compressive strength cement monolith with no free liquid present," explains Hughes. "There is a bit of air space in the container after the lid is automatically riveted on."
After the containers are sealed, each is thoroughly checked for radiation leakage. Carr estimates there will be 7,000 containers shipped from this facility by the time the job is finished early in 2006.
"We do all the inspection inside the Remediation facility," says Carr. "We have one the larger staffs of radiation technicians on site as any place in the world."
The containers move to the end of the building for final loading. Cranes lift and position the containers into specially designed cradles for transport. A polymer cap, part of the tie-down system, is installed on the cylinder. The entire unit is secured to the bed of the trailer with cables and turnbuckles. Radioactive Class 7 placards are placed on the front, back and sides of the tractor-trailer rig in accordance with Department of Transportation requirements. The tractor-trailer rigs are inspected for road worthiness and only certified operators do the driving.
The specially designed flatbeds are transported by an exclusive-use carrier, Visionary Solutions, Oak Ridge, Tenn. Once a truck leaves the site its movement is monitored. Department of Energy (DOE) and Fluor track the shipment through two-way communications systems in the vehicles. DOE has radiological assistance teams in place across the country to provide on-scene commanders with radiological monitoring coordination. The route from the site to Waste Control Specialists, LLC (Andrews, Texas) is approximately 1,340 miles. Containers are being held there until approval for permanent disposal is given.
Every conversation with Carr and others at the Fernald Project site begins and ends with safety. Oversize bumper stickers on the backs of cars and trucks remind drivers to fasten seat belts. Placards and posters with safety messages abound. Regardless of the type of hazardous material being handled, Carr says, you must respect what you're handling. He alludes to problems (political and environmental) this site had in the latter stages of its operation. With some hesitancy, Carr says, "Years ago, some people here got too used to handling uranium and other material. They began to think of it as just dirt."
You have to plan how you will handle the material and have the right people with the right tools in place to do so. "We ran a simulation of this process for about five months," Carr adds, "before we even started to build."
Work disciplines and authorization of who will handle what are also essential. "Working with any hazardous material requires maintaining control," he advises. Education is high on Carr's list for safely handling hazardous material.
"Knowing what it is and what it does is part of the equation," he says. "Knowing the intent of the requirements [for handling] makes you aware of the seriousness of the job."
In the early stages of the project many of the construction workers on site were more used to building stadiums and other structures. Working under the restrictive conditions of this project was new. When dealing with new people, and temporary or third-party providers, says Carr, compliance with safety regulations becomes critical.
"The way we do it," he says, "is to use color-coded hard hats for the new people when they arrive. We also use a mentoring program [for six months] to help orient the new person, give them a positive example to follow and explain requirements to them."
The color of a person's hardhat immediately identifies him to everyone on site. It means anyone can offer help or instruction if they see a need. After a trial period, the person moves up and changes the color of his hat. Part of that watching-outforothers means noticing if a person's protective gear is torn, etc., as well as watching for unsafe work practices.
"When handling hazardous material," explains Carr, "it's important that the person know what the job is he's being asked to do. We walk through the job with a person before he does anything. Management has to take responsibility for the person and be responsive to suggestions."