The purgatory of radioactivity

Similar waste was previously handled at locations in UMore Park in Rosemount.
Facility director Andy Phelan stands before three massive tanks that hold liquid chemical waste collected from the university and schools across the state Friday at the Thompson Center for Environmental Management. Liquid waste is stored in the tanks before being transported by a private company for disposal.
February 03, 2011

In an average week, more than five tons of waste from across the state is trucked into an unassuming, one-floor brick building on the edge of the University of Minnesota’s Minneapolis campus.

The Thompson Center for Environmental Management is not the final destination, but rather a sort of purgatory for chemical waste ranging from latex gloves that have been in contact with chemicals to low-radioactive materials from research labs.

Similar waste was previously handled at locations in UMore Park in Rosemount, Minn. and in the Como neighborhood, but safety concerns rose to the state Legislature.

The debate concluded in 1994 with the $8.1 million University building that processes more than 600,000 pounds of toxic trash every year, consolidating nearly all of the state’s hazardous waste.

Since its construction, the area around the Thompson Center has transformed from parking lots and open space. The center is now in the shadow of TCF Bank Stadium and the proposed sites of several new University buildings. Like the waste it processes, the Thompson Center might be temporary, but Phelan said it’s the best location available.

“We couldn’t get a good spot on the Mall,” facility director Andy Phelan said jokingly.

A prison of radioactivity

Twice every week, and once a week in St. Paul, specially marked trucks pick up chemical waste from the campus and bring it to the Thompson Center.

“It really is just like common household trash, except that it is research lab trash — like gloves and paper,” Phelan said. “The radioactive material is usually absorbed into it, and extracting it would be impossible.”

The facility is filled with 500 sealed containers of low-radioactivity gloves and paper, the byproducts of more than 1,000 laboratories on campus.

“[The labs] have materials, some common, which might have special hazards,” Phelan said. “If we just hold it on shelves for a couple of years, all the radioactivity will be gone.”

While the vast majority of the waste at the Thompson Center is made up of gloves and sheets of paper, there are also low-radioactive materials.

A cancer researcher, for example, might use low-radioactive materials in pursuit of new forms of chemotherapy, said David Paulu, who started at the lab as a University student nine years ago. That waste, arriving in special drums or boxes, is sorted on rows of shelves until radioactive decay runs its course and the items no longer pose a threat.

The waste will sit for 15 to 20 half-lives, Paulu said, referring to the amount of time a substance takes to decay to half of its size. The common half-life for the substances that are stored in the facility ranges from eight to 90 days, said Paulu.

Wastes take a couple of months — but sometimes as long as a few years — at the Thompson Center before being picked up by a third-party vendor. A truck comes once a year to transport radioactive waste to a facility in Tennessee for additional processing before being dumped in a special radioactive waste landfill in Utah.

A good 30 miles from civilization, the Clive Disposal Facility, owned by nuclear waste company EnergySolutions, is surrounded by the Utah desert, essentially in the middle of nowhere, said Mark Walker, spokesman for EnergySolutions.

The location was selected by the U.S. Department of Energy after researching 29 locations in that state, Walker said.

The trash is compacted and stored on just a square mile of property where it is stacked to 38-foot-tall pyramids.

Fully equipped safety features

Equipped with layers upon layers of safety, very few accidents have occurred at the lab in its 16 years.

Maybe once a year, Phelan said, someone at the facility will drop a bottle of a gas.

Even if waste gas is released, negative air pressure in the facility contains the gases and ventilates them harmlessly into the atmosphere.

“As soon as that bottle hits the ground, the sensors go off, the message goes to a remote centralized monitoring center and they call me,” Phelan said.

Large ventilation fans constantly change the air in each room up to 18 times an hour.

Two fire suppression systems and a water sprinkler system guard the offices and storage areas. Designated hazard areas are protected by a foam-based system that better addresses unstable solvents.

Floors in the storage areas have ramps and are raised to accommodate the foam in the event of an emergency, and special floor tiles in each storage room are chosen by evaluating its chemical resistances.

Besides having the responsibility for storage and repackaging of hazardous waste, the Thompson Center also responds to chemical spills on campus.

Last September, an on-call Hazmat crew from the University’s Department of Environmental Health and Safety, along with at least eight fire trucks, responded to a spill of a flammable chemical, pyridine, at the Phillips-Wangensteen Building.

The two students who spilled several liters of the hazardous chemical were sent to the hospital, and two blocks of road were closed because of the accident.

Phelan remembers long ago that chemical spills were a common occurrence at the University. Now, he said, spills are rare but still happen two or three times a year.

“People still cut corners.”

The future

Centrally funded by the University, school researchers do not have to pay for the services, but outside organizations can pay a fee to have their waste picked up and disposed.

“They have been the vendor of choice for a long time before I was here,” said Erin Paulson, safety administrator for Winona State University.

Running the program costs about $1.6 million a year. The facility receives nearly $500,000 in fees from hospitals and schools.

“The amount of waste has been remarkably consistent [in 16 years] given the fact that research, which is our biggest customer, has skyrocketed,” Phelan said.

One explanation he offers is a new way to conduct research called micro-scaling.

“It’s scaling down and getting the same quality of research using more sophisticated machines,” allowing the use of smaller and smaller amounts of chemicals or none at all, Paulu said.

It is part of the “green movement” of chemistry, he said.

“We’d like to think there will be no chemicals at the University,” Phelan said hyperbolically of the future.

As more of the population continues to physically extend toward the facility, the possible relocation of the Thompson Center will come into question.

Moving to St. Paul is possible, Phelan said, but because more of the waste comes from Minneapolis, having the facility at its current location is more convenient.

“I would like to see it stay here, but I don’t know what the master plan is,” Phelan said. “The value of this real estate might be deemed more amenable to a research laboratory.”

Phelan, who also worked at the two now-defunct storage sites, has been at the Thompson Center since it opened. He said several academic institutions now have similar on-campus sites modeled, he thinks, after the Thompson Center.

“It was by far a unique facility for an academic setting.”

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