Los Alamos National Laboratory, as seen in a December, 2014 image. Photo: Los Alamos National Lab Facebook

The same work crew, same room, and same equipment involved in a plutonium handling mishap at Los Alamos National Laboratory in mid-August had another serious event just over a month later, according to a federal report.

The airborne plutonium was released when pipefitters attempting to replace two elbows on the service panel removed a plug, according to the Defense Nuclear Facilities Safety Board weekly report, dated Sept. 29.

“The pipefitters described difficulty in turning one of the elbows because of an interference from a plug and decided to remove the plug thereby releasing the contamination,” the report states. “They believed they had allowance to take such an action because the work document provided only vague constraints on ‘field routing.’”

Three of the workers – two pipefitters and a support radiological control technician – were wearing respirators and anti-contamination clothing, which showed readings of trace plutonium. One of them had 100 k dpm alpha radioactivity levels on their skin in the chest area – which was successfully decontaminated.

“This was the same work crew and glovebox involved in the contamination event late last month,” they add.

The other event was a “criticality safety event” that occurred on Aug. 18 – and resulted in a two-hour quarantine throughout the plutonium facility.

The crew who were at work attempting to move a shell in the subject laboratory “did not utilize a required use-every-time attachment to the material move procedure,” according to the DNFSB report describing the event.

The shell was moved into a location that already contained plutonium metal, which violated the lab’s limit to avoid criticality events.

That was on a Friday – the violation was discovered the following Monday. The work crew then tried to remedy the situation without following protocols requiring them to notify other personnel, the report adds.

“Following discovery, the crew conducted two additional nuclear material movements that they felt were necessary for product quality and security, rather than declare a potential process deviation as required by procedure and training,” it states.

Contamination was found on 11 workers, mostly on their protective booties. The theory of the spread of the plutonium was that “small drops of liquid from the system, which had been previously sampled and found to be below detection levels, were actually contaminated (or became contaminated during the course of the job) and the liquid spread beyond the room as a result of the job,” the report adds.

The two latest incidents are likely to increase alread-heightened scrutiny on the national laboratory, which was founded in 1943 as the centerpiece of the Manhattan Project. A 2016 report card of the nation's nuclear facilities found that Los Alamos was the only one graded "red," indicating safety lapses. The laboratory was also the focus of a six-part series entitled "Nuclear Negligence," published in June by the Center for Public Integrity. That in-depth look at the nuclear safeguards - and especially the criticality events - began with a 2011 incident in which workers gathered eight plutonium rods together for a photo-op. That event and a 2013 reassessment of the laboratory's plutonium capabilities have shut off entire portions of the laboratory for roughly four years, according to the report.