Fluor Idaho still does not have a date for resuming sludge repackaging inside the building at Energy Department’s Idaho National Laboratory where four drums of the radioactive waste overheated and blew off their lids on April 11.
That is a key takeaway from a monthly report the lab’s cleanup contractor filed Oct. 30 with the Idaho Department of Environmental Quality. The monthly update, which covers progress made in the recovery from the incident from Sept. 19 through Oct. 22, also said the company expects to complete a “corrective action plan” in November.
The accident happened inside the Accelerated Retrieval Project 5 building, within the lab’s Radioactive Waste Management Complex. ARP 5 is a fabric building where workers remove aerosol cans and other forbidden objects from drums of sludge waste buried for years at INL after being shipped from the former Rocky Flats nuclear weapons plant in Colorado. The drums are ultimately certified for off-site disposal, although none of the four 55-gallon drums had been approved for shipment.
Details of the fix-it plan have not been released, but it will be based on Fluor’s formal cause analysis published Oct. 25. The 350-page evaluation found the breaches happened after depleted uranium inside the drums contacted air for the first time in about 40 years, and that the company should have taken greater care in processing and repackaging sludge waste.
The report also faulted Fluor Idaho for not doing more to identify potential combustion sources inside the drums. While there were no injuries, that was partly because the incident occurred after 10 p.m. when there were no employees nearby.
The company has gotten up the spilled radioactive sludge from the floor and walls of the room where the drum breach occurred. Fluor Idaho has not said how much the accident, and its resulting cleanup, and investigation will cost. Since 2012, the ARP site has safely processed and repackaged about 9,500 drums of sludge waste, according to Fluor Idaho.
At the site of the incident there were about 31 containers that had been treated, apparently including the four drums that overheated and ejected their lids, and 15 that were awaiting treatment, Natalie Creed, hazardous waste unit manager for the Idaho DEQ, said in an email.
After processing at ARP 5, the containers are assayed again at the Advanced Mixed Waste Treatment Project (AMWTP) to determine if they are classified as transuranic (TRU) waste. If they are TRU waste, they go through the certification process for transport to DOE’s Waste Isolation Pilot Plant in New Mexico. If not, they could go elsewhere such as the EnergySolutions waste disposal facility in Utah, Creed said.
The Energy Department formally notified the state on Sept. 28 it would not meet the INL Site Treatment Plan (STP) milestone to treat and certify for shipment to WIPP all TRU waste covered by a 1995 settlement agreement between the state, DOE, and the U.S. Navy regarding nuclear waste in Idaho.
