Repackaging of radioactive sludge waste at the site of an April 2018 drum breach at the Department of Energy’s Idaho National Laboratory is nearly complete, according to a monthly report filed with the Idaho Department of Environmental Quality.
Site cleanup contractor Fluor Idaho has completed processing all material except three waste trays inside the Accelerated Retrieval Project No. 5 (ARP-5) facility within the lab’s Radioactive Waste Management Complex, according to the June 27 update.
The company expects to finish the remaining waste processing this month, the update says.
There were about 41 waste drums left to be repackaged into new drums in ARP-5 Room 106 at the time of the accident, in which four drums overheated and blew off their lids, spewing sludge onto nearby walls and ceiling. Fluor Idaho says the temperature inside the drums increased to about 150 degrees Celsius after depleted uranium contacted air for the first time in years. Also, material from the drums generated methane, a flammable gas.
The contractor paused processing remaining waste while the Energy Department conducted additional tests to ensure waste in the trays is not too hot.
The sludge waste inside the 55-gallon drums involved in the accident was first generated decades ago at the Rocky Flats nuclear weapons plant in Colorado. The waste, buried on-site at the Idaho National Laboratory for years, was being repackaged inside the ARP fabric filter building.
The accident was unusual in that the overheating occurred hours after the waste was removed from the old drums and contacted the air. Typically, such overheating, if it occurs, will happen within a few minutes, according to reports filed with the state and DOE about the accident.
