Tune for cleanup of U-233 changes

Nuke material to be disposed of, and cost to do so has nearly tripled to $379M

By FRANK MUNGER, December 11, 2006

OAK RIDGE - The U.S. Department of Energy has revised its strategy - and its price tag - for one of the most challenging nuclear projects in recent history.

The government's goal is to get rid of a large stockpile of uranium-233 stored in a World War II-era building at Oak Ridge National Laboratory.

The newly estimated cost is $379.2 million, according to Steve McCracken, the environmental cleanup chief in Oak Ridge. That's almost triple the $128 million DOE announced when awarding a contract for the project in 2003.

But McCracken said the original figure did not cover all aspects of the work, such as the cost for shipping containers, associated work at another nuclear facility, long-term storage of materials and about $70 million included for "risks and uncertainties."

The actual cost growth was from about $250 million to the current level, he said.

The nuclear stockpile has been in storage at ORNL since the 1960s. It is a legacy of experiments conducted under the auspices of the Atomic Energy Commission, a federal predecessor to DOE, which was interested in using U-233 as a fuel for nuclear reactors.

"Obviously they need to deal with the material. They should have dealt with it long ago," said Susan Gawarecki, executive director of the Local Oversight Committee, which evaluates environmental issues for local governments in the Oak Ridge area.

The project was altered this year after Congress instructed DOE, as part of a 2006 appropriations bill, to scrap plans to extract medical isotopes from the nuclear stockpile. So DOE is moving forward with disposition of the material, even though critics say that radioisotopes could be used in life-saving cancer treatments.

Oak Ridge officials issued a revised environmental assessment Dec. 6 and said they would accept public comment through Dec. 22. That's a relatively short comment period, but DOE said it's sufficient because the potential impacts are still pretty much the same as in an earlier review.

The plan, in general, is to modify the existing storage facility - Building 3019-A at ORNL - and install equipment needed to process the U-233 to eliminate its weapons capability and to prepare it for disposal.

That will be accomplished by "down-blending" the U-233 with stocks of depleted uranium, which have most of the fissile isotopes already removed.

According to the draft report, DOE intends to acquire the necessary depleted uranium from the agency's Savannah River Site in South Carolina. Even though tons of depleted uranium are stored in Oak Ridge, none of it was deemed suitable for this particular project, the report said.

About 225,000 kilograms of depleted uranium will be shipped from Savannah River to the Nuclear Fuel Services plant at Erwin, Tenn. It will be processed and converted to uranyl nitrate, a chemical form needed for the next step, and transported to Oak Ridge.

The down-blending is expected to begin in July 2012, with project completion scheduled for 2016, said Walter Perry, a DOE spokesman.

Isotek Systems Inc., a partnership involving EnergySolutions, Burns and Roe, and Nuclear Fuel Services, is the contractor on the project.

Once the enriched uranium is down-blended and converted to an oxide form, it will be removed from Building 3019-A, a 63-year-old structure that critics have said is vulnerable to terrorism. The repackaged materials will be stored at a site in Melton Valley west of ORNL until a disposal site is approved.

Lance Mezga, a geologist who heads a citizens board that advises DOE on environmental matters, said he's confident the technical expertise is available to do the job safely. The advisory board, however, continues to raise questions about the ultimate disposition of the material, he said.

"We don't want to continue storing these materials on site for a lot of reasons," Mezga said.

John Owsley, the state's environmental oversight site chief, said it's possible the radioactive waste could be shipped to the Waste Isolation Pilot Plant in New Mexico or the Nevada Test Site for disposal.

The inventory of U-233 is contained in about 1,200 canisters, which are housed in shielded tube vaults inside the ORNL building, DOE said. An earlier risk assessment indicated the containers were in pretty good shape, although minor corrosion has taken place, the report said.

After the down-blending work is completed, Building 3019-A will be decommissioned. That, too, could be a hazardous adventure.

The building once housed operations that chemically processed fuel from the nearby Graphite Reactor. In 1959, a chemical explosion "distributed plutonium contamination throughout the interior and exterior of the building." Although a cleanup project was done at the time, radioactive particles remained behind, and workers painted the walls to prevent the spread of contamination.

In addition to the radioactive hazards, Building 3019-A has uncoated lead shielding, lead paint, polychlorinated biphenyls, asbestos and other hazards. There also is an "underground ventilated bunker" that contains about 4,000 gallons of thorium nitrate solution that's contaminated with U-233.