Three workers at Los Alamos National Laboratory were contaminated on the job last month when an accident released radioactive material into the air and sent it spreading through a wing of the lab’s plutonium facility.

It was the second time in four weeks that lab workers were exposed to radioactive particles at the facility, and the same crew was involved in both events, according to a weekly report from the Defense Nuclear Facilities Safety Board, an independent adviser to the U.S. Department of Energy.

The Sept. 23 incident was the most recent in a series of accidents at the lab, including one in August that violated federal safety protocol established to prevent a runaway nuclear chain reaction. In that case, reports said, workers had mishandled radioactive metals.

While the safety board’s report does not state what type of radioactive material was involved in the September incident, the plutonium facility is where the lab processes highly radioactive plutonium and where work to create plutonium pits — the softball-sized fission triggers inside nuclear bombs — has been ramping up since late 2015.

Lab spokesman Matt Nerzig said in an email, “None of the three workers received any measurable dose, and there was no risk to the public. The facility’s safety systems worked as designed.

“The Laboratory’s work with nuclear materials on behalf of the country is complex, challenging and comes with inherent risks,” Nerzig continued. “The safety systems and procedures in place at the Laboratory’s plutonium facility are designed to greatly reduce the risk to Laboratory employees, the public and the environment, and make it the safest place for this type of work.”

According to the safety board report, radiation was released into the air after two pipefitters unintentionally removed a plug from a glove box — a chamber affixed with gloves that is designed for safe handling of nuclear materials and other hazardous substances. The pipefitters, who had been working on upgrades to a waterline under the glove box, said the plug had been blocking their ability to replace parts of a service panel, and they believed their work order allowed them to remove the plug because the order “provided only vague constraints.”

The workers and a radiation control technician were wearing protective clothing and air purifying respirators, the report says, but they “exited the room when airborne radioactive contamination levels exceeded their safety thresholds.”

The clothes of all three workers were contaminated, as was the skin on one workers’ chest, “which was successfully decontaminated.”

Nerzig confirmed that, saying, “The worker that received skin contamination was successfully and thoroughly decontaminated — mostly by washing off the contamination with water.”

There was no indication that any of the workers inhaled the airborne radiation, the report says. The workers also were placed on “special bioassay,” a program to monitor the amount of radiation inside a person’s body.

The incident occurred on a Saturday, outside of normal working hours. The safety board advised the lab to ensure “adequate on-call support during off-hours.”

It also raised concerns about “workers’ perceptions of increased programmatic pressure for project work.”

Similar issues were cited earlier this year after a worker was fired for improperly shipping plutonium out of state by air, rather than by truck, violating federal regulations. That incident occurred on a Friday, when some workers and managers had the day off because of a rotating work schedule. The worker who had made the shipping error believed there were time constraints that called for a quick shipping option, though the laboratories that were receiving the material later said there was no such urgency.

In August, work paused for two hours at the plutonium facility after radiation was found on 11 workers who had been removing a chilled water supply that contained more contamination than they realized before the work began.

The most recent safety board report cites 17 “areas of concern” at the plutonium facility related to potential problems with air circulation and water if a fire were triggered by a seismic event. The board long has questioned the building’s stability, which was a key issue raised during a hearing in Santa Fe in June between board members and senior Energy Department and lab officials. The hearing was scheduled to assess the lab’s ability to handle increasing nuclear materials as part of the National Nuclear Security Administration’s goal of producing as many as 80 plutonium pits per year by 2030.

The National Nuclear Security Administration is preparing an analysis of the lab’s ability to complete the work in the coming years, compared to other Energy Department sites. That report was supposed to be released in late summer but has not yet been made public.

Meanwhile, questions have been raised about whether the safety board will continue to operate under the Trump administration.

In June, the safety board’s new chairman, Sean Sullivan, wrote a letter to the White House saying that the board’s work is redundant and that doing away with it could save $31 million annually. Other members of the board strongly objected to Sullivan’s letter, saying the board provides crucial objective oversight.

Contact Rebecca Moss at 505-986-3011 or

(0) comments

Welcome to the discussion.

Thank you for joining the conversation on Please familiarize yourself with the community guidelines. Avoid personal attacks: Lively, vigorous conversation is welcomed and encouraged, insults, name-calling and other personal attacks are not. No commercial peddling: Promotions of commercial goods and services are inappropriate to the purposes of this forum and can be removed. Respect copyrights: Post citations to sources appropriate to support your arguments, but refrain from posting entire copyrighted pieces. Be yourself: Accounts suspected of using fake identities can be removed from the forum.