The Department of Energy will need an extra year to prepare a report on long-term disposal options for commercial and nonweapons radioactive waste, some of which could be sent to Hanford.

The schedule has slipped as DOE has greatly expanded the potential amount of waste to be studied, said Christine Gelles, director of DOE's environmental management office of disposal operations, during a visit to Richland last week.

A draft environmental study on the waste now is expected in early 2009 with a final study finished in early 2010.

Then DOE is required to report to Congress before making a formal decision on what to do with the waste.

The waste, called Greater Than Class C waste, initially included an estimated 7,280 cubic yards of radioactive metal from decommissioning commercial nuclear power plants and waste from other industrial uses, such as sterilizing medical equipment, treating cancer and testing welds.

But since work began on an environmental study on the waste, an additional 39,000 cubic yards have been added to the study for potential disposal. Much of that would be produced under the Global Nuclear Energy Partnership, which is proposing building an Advanced Fuel Cycle Facility to develop ways to reuse nuclear power fuel.

That project, if it goes forward, would produce debris, such as clothing, contaminated with radionuclides classified as transuranic. DOE has typically sent such waste generated in nuclear weapons projects to deep geological repositories, such as the Waste Isolation Pilot Plant for transuranic waste in New Mexico.

It's considering 10 disposal options in the study, including deep geological repositories in New Mexico and Nevada.

Hanford may be more likely to be considered for waste that includes radioactive metals from decommissioned power plants. That waste also has increased since the report began from 3,380 cubic yards to about 9,600 cubic yards.

Although it's a relatively small amount of waste by volume compared to the low-level waste from past plutonium production to be disposed of in Hanford landfills, its radioactive content is significant. The original 3,380 cubic yards in the study has 110 million curies of radioactivity, which compares to 190 million curies in the 53 million gallons of waste awaiting treatment in Hanford's underground tanks.

Although the waste is considered low-level radioactive waste, the greater than class C designation indicates it's the most radioactive category of that waste.

The additional waste added to the study includes waste from new commercial reactors and from two West Valley, N.Y., nuclear burial sites that might be excavated. Most of the waste will be generated after 2035. Although the study originally included waste generated up to 2062, that may be extended.

The waste could be disposed of in a vault or in trenches with protective barriers and waste packaging. Also under consideration are deep bore holes topped with drilling deflectors to guard against people inadvertently disturbing the waste far into the future.

In addition to Hanford, DOE also is considering commercial disposal in unspecified locations and one or more sites in New Mexico, Nevada, Idaho, South Carolina and Tennessee.