There were at least six separate contamination incidents at Los Alamos National Laboratory between December and January, according to a series of safety watchdog reports.
Most recently, two incidents occurred within a week in early January in Technical Area 55, according to summaries by the lab.
Just before 6:30 p.m. on Jan. 4 an employee at the lab’s Actinide Material Processing and Power, Power Supply Production group alarmed a hand and foot monitor at Technical Area 55, where among other work plutonium is worked into pits for use in nuclear weapons.
A particle was detected on the worker’s left index finger. A radiological control technician analyzed the employee, removed the particle and collected nasal smears that came back with no detectable activity. No other contamination was found and “there was no further impact to personnel health, safety, the facility, or the environment,” according to the lab.
Two days prior, in the same area, an employee with the same work group set off a hand-and-foot monitor and contamination was found on the person’s right palm. The employee was decontaminated until no contamination could be detected.
Another incident occurred on Dec. 13 when an employee at the Waste Characterization, Reduction, and Repackaging Facility was working to remove legacy contaminated equipment from a glovebox enclosure, “which is highly contaminated and has a legacy hydraulic oil spill,” according to a report from the Defense Nuclear Facilities Safety Board (DNFSB).
The workers were wearing two pairs of Tyvek coveralls and powered air-purifying respirators. One of them entered the enclosure and set off monitoring equipment when they exited, the DNFSB said in a report on the incident. When the employee took off a pair of protective coveralls, contamination was found on the inner elbow.
Radiological control technicians had limited decontamination equipment at the site, so the worker was transported to Occupational Medicine where he was successfully decontaminated, the DNFSB said.
On Dec. 5 a worker alarmed the final set of hand and foot monitors prior to exiting the PF-4 Plutonium Facility, located in Technical Area 55. Responding radiological control personnel identified skin contamination on the individual’s hand and successfully decontaminated them, DNFSB said in a separate report.
“The contamination was a particle, which are difficult to detect. The worker, wearing a lab coat and booties as personal protective equipment (PPE), had not been performing hands-on work but was acting as an escort for carpenters performing preparatory activities for decontamination and decommissioning (D&D) in a laboratory room,” the DNFSB said.
“During active D&D in this room, additional PPE is required, and the room is subsequently decontaminated to allow lab coat access,” the board wrote. “The room has had several contamination spreads and PPE contamination events over the past several weeks during active D&D and was the most likely source of the contamination.”
On Dec. 4, there were two related contamination events in the low-level waste area of the facility’s basement, the report said. Contamination was found on one worker’s personal protective equipment (PPE) after which a new crew on the next shift, along with a radiological control technician, inspected the waste bags that were the probable source of the first contamination.
Despite not finding any damage to the bags, three workers discovered PPE contamination during full body surveys, and a continuous air monitor alarmed as they exited the basement. No other personnel in the basement had any contamination detected on their PPE, but there was contamination detected on the low-level waste staging bins.
Low-level waste staging, labeling, and bagging practices are under evaluation to help prevent recurrence of this type of event, the DNFSB said.
