IDAHO FALLS, Idaho – Challenging waste types and uniquely shaped waste containers have kept things interesting for employees of the DOE Idaho National Laboratory (INL) Site’s Advanced Mixed Waste Treatment Project (AMWTP).
Those challenges have required the employees to adapt the AMWTP facilities to ultimately dispose the waste and containers.
During the 16-year mission to retrieve, characterize, treat, certify, and ship for disposal 65,000 cubic meters of transuranic and low-level wastes, AMWTP received tens of thousands of 55-gallon drums and boxes in various conditions.
Those elements presented obstacles, such as containers too large to fit into the boxlines for resizing and repackaging. The boxlines are huge concrete and metal hot cells where the containers of radioactive waste are opened and sorted without exposing workers to hazardous materials inside.
Most recently, AMWTP treated waste containing the reactive metal uranium. Operators used robotic arms to dump the waste contents into trays and rake through the material. The waste was repackaged and compacted in the facility’s supercompactor before being safely shipped offsite for permanent disposal.
“It all went according to plan,” said Nate Loftus, project manager with Fluor Idaho, EM’s INL Site cleanup contractor. “We had modified our procedures and put safety processes in place to protect our employees and facilities. This was yet another example of how effective our workforce is at adapting and completing our cleanup mission.”
In another recently completed project, crews resized gloveboxes containing waste and other large debris after opening 12-foot-high waste boxes from laboratories at EM’s former Mound Site in Ohio during the Cold War. The challenge of that project was safely dispositioning the waste contaminated with plutonium-238, an extremely fine, dust-like material.
Enclosures with reverse airflow and extensive high-efficiency particulate air filters allowed employees — wearing personal protection equipment and using supplied breathing air — to safely open the boxes and resize the materials. A separate enclosure was erected at the nearby Accelerated Retrieval Project VII facility where workers used tools, such as reciprocating saws, to reduce the size of gloveboxes.
Another success story involved the disposition of 30 boxes containing high-activity isotopes. To prepare for processing this waste, employees developed new procedures, conducted engineering evaluations, drafted new radiation control requirements, and completed additional training.
Crews opened the boxes inside a boxline using a robotic arm, transferring the contents to a metal trough where the waste was separated into smaller, lower-activity amounts. Then they moved the segregated debris through a port into an awaiting drum.
Fluor Idaho also deployed a new system to characterize the contents of some containers by measuring their dimensions and entering them into a computer program. This system was helpful when workers couldn’t obtain valid results due to the shape or configuration of waste in several hundred containers.
For that work, employees also used data from a camera that maps gamma rays emanating from the containers and locates portions with high levels of radiation. The system then characterized the gamma rays and determined specific isotopes and radioactive quantities. The technology also double-checked waste characterization assessments for consistency.
“Putting the system into use allowed us to provide the specific characterization data required by WIPP,” Fluor Idaho Manager Ed Gulbransen said. Waste treated at AMWTP is sent to the New Mexico repository for permanent disposal.