Idaho Crews Reprocess Packaged Waste, Ensuring Safe Shipment to WIPP

Crews are re-treating and repackaging previously containerized transuranic waste at the Advanced Mixed Waste Treatment Project at the Idaho National Laboratory Site to ensure its safe shipment to the Waste Isolation Pilot Plant in New Mexico.

IDAHO FALLS, Idaho — The U.S. Department of Energy Office of Environmental Management (EM) is nearing completion of a campaign in Idaho that involves reconditioning previously containerized transuranic waste to allow its safe shipment to the Waste Isolation Pilot Plant (WIPP) in New Mexico for permanent disposal.

The waste originated from the Advanced Mixed Waste Treatment Project (AMWTP) at the Idaho National Laboratory Site, where 55-gallon drums containing the waste were crushed in the facility’s supercompactor using 4 million pounds of force to form compact "pucks," reducing volume for shipping and storage. The supercompactor is known as the facility’s workhorse.

During compaction, liquids and solids are often squeezed out of the drums. Liquids known as squeezants are collected in the supercompactor's sump, then moved to 4-liter jars and placed into 55-gallon drums. Workers had added an absorbent to those drums and blended the contents with other debris. Next, they partially crushed the drums to avoid further leakage and overpacked them with 100-gallon drums.

In 2022, two shipments of that waste destined for WIPP were returned to the Idaho Cleanup Project (ICP) after drums developed pinholes during transit and leaked a small amount of liquid inside the shipping casks. Crews had filled those drums with squeezant pucks years before and placed the drums in storage at AMWTP before they were shipped to WIPP. As a precaution, ICP contractor Idaho Environmental Coalition (IEC) suspended all shipments of that waste.

Crews later reopened the containers holding the pucks at AMWTP using a robotic arm, retreated the waste with absorbents, inspected it to ensure no prohibited items, including liquids, were present, and then performed compaction in the supercompactor, eliminating void spaces.

IEC AMWTP Treatment Facility Operations Manager Don Barnett said the campaign has progressed well.

"We had a slow start to the fiscal year due to planned maintenance and minor equipment issues, but we picked up the pace, and things are running smoothly now," he said.

Barnett noted that AMWTP teams completed an EM milestone of processing 150 drums seven weeks early and continue to make progress on the remaining inventory. Just 56 drums remain to be processed.

-Contributor: Erik Simpson