Up to 9,000 containers of radioactive Hanford waste could be sent to Idaho for repackaging under a revised Department of Energy plan.

DOE announced last week that it plans to make Idaho National Laboratory the nation's primary processing center for transuranic waste from nuclear sites that don't have their own processing capability.

At Hanford, transuranic waste is typically building, laboratory and other debris contaminated with plutonium. It temporarily was buried after 1970 when Congress ordered the waste to be sent to a national repository but before the Waste Isolation Pilot Plant, or WIPP, was opened in New Mexico to permanently dispose of the waste.

By sending some Hanford waste to Idaho, DOE believes it can be packaged more efficiently than with the manual process that would have to be used at Hanford. The packaging allows fewer shipments to be made to WIPP and less of WIPP's limited disposal space to be filled.

Much of Hanford's retrieved transuranic waste can be surveyed and packaged for shipment at Hanford. But contractor Fluor Hanford is retrieving increasingly corroded 55-gallon metal drums of waste that are so degraded they have to be slipped inside an 85-gallon overpack.

About half of those overpacked drums have to be repacked manually at Hanford because they contain waste not approved for shipping or acceptance at WIPP. For instance, aerosol cans must be removed and other waste poses the risk of hydrogen generation without repackaging.

But DOE expects to retrieve about 9,000 containers that will require an overpack but not need repackaging because of their contents.

Those containers will be sent to Idaho for compaction at its Advanced Mixed Waste Treatment Facility, said Mark French, DOE project director. It can compress several 55-gallon drum into a 110-gallon drum, he said.

Now the overpacked drums are being stored at Hanford if their contents do not require repackaging. Although the 85-gallon overpacks could be sent to WIPP, shipping trailers are configured to carry only 12 of the overpacks compared to 42 of the 55-gallon drums.

In addition, the overpacks do not make efficient use of limited repository space and WIPP is not equipped to load and stack the drums efficiently, French said.

Some oversize boxes of waste also may be sent to Idaho for repackaging. However, because only the boxes measuring up to 5-by-5-by-8 feet can be sent to Idaho, Hanford still will require a planned Large Package and Remote Handled Waste Packaging Facility.

DOE headquarters gave written approval of the need for the project in December. It would be used to package waste that workers cannot be near because of its high radioactivity in addition to large boxes of low level and transuranic waste.

No schedule has been set for when Hanford will begin shipping its backlog of overpacked transuranic waste to Idaho. It's one of 11 sites that will send transuranic waste to Idaho, and DOE may choose to send waste from smaller sites first to allow them to be closed.

In 1998, DOE said in a record of decision following an environmental impact study that Hanford could be one of four sites where transuranic waste was shipped from sites without their own treatment and packaging capabilities. The new DOE policy amends that record of decision.

DOE agreed in 2006 to resolve a lawsuit brought by the state of Washington not to send transuranic waste to Hanford at least until a new environmental study, the Hanford Tank Closure and Waste Management Environmental Impact Statement, is completed. A draft of that report could be ready in August.