Idaho state regulators are reviewing documents drafted by Fluor Idaho, which the company hopes will allow resumption of sludge repackaging this spring at the Idaho National Laboratory facility where four waste drums overheated and ejected their lids last April.
The “corrective action plan” and “evaluation of the safety of the situation” reports are being discussed by the state and the Department of Energy, Brian English, hazardous waste permits manager with the Idaho Department of Environmental Quality, said by email March 15.
The documents have not been “formally submitted” yet with the “proper certifications,” English said in a Wednesday follow-up email. Once that happens DEQ will examine the reports to determine if the hazardous waste issues are adequately addressed, he added.
The state will formally review the plans “and concur or require additional information/actions up to modification of the permit,” according to English.
The cleanup contractor at the Idaho National Laboratory told the state on Feb. 28 it wants to resume radioactive sludge repackaging in April at the Accelerated Retrieval Project No. 5 facility within the Radioactive Waste Management Complex.
The documents outline various steps, most of them due to be completed this month or next, that should minimize the chances of such an event occurring again. The measures include additional staff training, further waste characterization, and safety culture improvements.
Fluor Idaho did not respond to a request for comment on the process.
Because the drums involved in the event were shipped from the Advanced Mixed Waste Treatment Project (AMWTP) to ARP 5, some of the corrective actions apply to AMWTP and other locations across the Idaho Cleanup Project, according to the 36-page corrective action plan. The AMWTP is at the center of processing efforts at INL for 65,000 cubic meters of waste that originated from the Rocky Flats weapons site in Colorado.
At about 10:30 p.m. on April 11, 2018, four 55-gallon drums of waste sludge overheated to about 150 degrees Celsius after depleted uranium contacted air for the first time in decades. The containers, originally Rocky Flats, were being reopened and the material repackaged after having been buried at INL for decades. No one was hurt in the incident, although waste ejected onto the ceilings and walls.
Three on-site firefighters responded to an alarm at the facility and found one drum with its lid off. The crew made an unsuccessful attempt to stop the first drum from smoldering and then exited the facility. Upon a subsequent re-entry days later, workers at the site discovered a total of four drums with displaced lids.
Sludge repackaging involves using equipment to open waste drums, removing or treating prohibited items on a sorting table, loading waste onto trays, and doing a visual examination of the work stations. Eventually, the waste is reloaded into new, vented 55-gallon drums.
Initial tests done in 2016 and 2017 on the parent drums of the four repackaged drums involved in the accident indicated they contained homogeneous solids, according to the report. Evidently, March 2016 communications between the AMWTP and ARP staff failed to identify the affected waste as a composite collection of homogeneous solids containers “from more than one waste generator and various waste generating processes.”
As a result, the waste containers involved in the accident were not as well vetted as they should have been, according to the report.
