It could take several more weeks to complete cleanup of an Idaho National Laboratory facility where four drums of solidified radioactive waste were found to have breached on April 11, the president of site cleanup contractor Fluor Idaho wrote in a May 25 column for local newspapers.
The investigation has entered a forensic phase, and waste samples from the drums at the Accelerated Retrieval Project 5 facility have been sent to outside laboratories for analysis, according to Fluor Idaho President Fred Hughes. “We expect to learn specifics about the waste and why it reacted after being processed and placed in clean drums.”
Workers have to date cleaned up one of six grids of the facility’s Airlock 5, where the drum breach occurred, Idaho Department of Environmental Quality (DEQ) Hazardous Waste Unit Manager Natalie Creed said by email.
The contractor just filed its first monthly report on the incident with the DEQ. The report said most of the cleanup of the floor around the breached drums should be done this month, the cause of overheated drums is unknown, and no date has been set for resumption of waste repackaging in the area where the breach occurred.
The cleanup has made progress. Since the lids on four drums came off during breach incident, Fluor has set up a video surveillance system and added monitoring devices to watch for any subsequent problems. It also checked the ventilation system for ARP 5, including replacing the filters to help ensure no dangerous materials escape from the building, DEQ Hazardous Waste Permitting Manager Brian English said by email this week.
The four drums, which have not been moved, are currently considered “safe” given no one without proper gear and training is allowed to enter ARP 5, English said. Fluor Idaho is also “using a vacuum or dust pan and brush” to gather up contaminated material in the area of the breached drums, he added.
Through this process, the recovery effort has partially filled four separate drums with material from the breached containers mostly fine dusts, but also some larger pieces of metal from the breached drums. The new drums are being only partly filled because investigators don’t yet know what caused the original drums to overheat, English said.
The drums that breached their lids contained sludge wastes generated during the 1960s at the then- Rocky Flats nuclear weapons site in Colorado and shipped to Idaho decades ago. At the Idaho National Laboratory, the material had been stored for years within a trench in a subsurface area. The material was dug up in the 1970s and placed in boxes or overpack containers on a pad at INL.
This sludge waste was again recently retrieved and was being repackaged in the ARP 5 building, where it was checked for forbidden items such as aerosol cans, English said. The waste had been processed and placed inside new drums, and had sat inside the ARP 5 area for several hours before the event, Hughes said.
Although INL briefly suspended off-site shipments of transuranic waste to the Energy Department’s Waste Isolation Pilot Plant in New Mexico, shipments resumed within a few days.
The Energy Department has said the drum breaches occurred before the waste cleared the protocols for shipment to WIPP.
