Correction appended.

Los Alamos National Laboratory failed an annual assessment of its program for ensuring that work surrounding nuclear weapons development is free of accidents that could lead to a nuclear chain reaction resulting in a release of radiation.

An evaluation of the lab’s nuclear criticality safety program in a report made public this month by the Defense Nuclear Facilities Safety Board, an independent advisory board that reports to the president, found the lab had two dozen “criticality” safety infractions in fiscal year 2016, which ended Sept. 30, most of which were self-reported by Los Alamos staff.

The lab was the only one among some two dozen nuclear facilities operating within the Department of Energy to receive a failing grade of “red.” Two others received “yellow,” defined as “adequate but needs improvement.” The rest were rated “green,” meaning they met or exceeded expectations.

Los Alamos had 23 low-level infractions, one mid-level infraction and no high-level infractions. The report does not detail the nature of the infractions. Sandia National Laboratory in Albuquerque had no infractions.

Los Alamos in fiscal year 2015 rated “yellow.” The downgrade for 2016 comes as the Department of Energy is considering ramping up production of plutonium pits at the lab. Plutonium pits are the softball-sized triggers used to set off nuclear weapons.

Kevin Roark, a spokesman at Los Alamos, said the lab has taken a series of actions to address issues in nuclear criticality, including improving operating procedure and both training and adding new staff.

He said lab managers were also “implementing new and rigorous criticality safety controls.”

Roark did not answer questions about where exactly incidents had occurred or if they were related to increased work in plutonium pit production.

The report was the latest in a series of assessments in recent years that have highlighted significant safety issues at Los Alamos. One of the most serious infractions allowed mixed-waste drums to be improperly packaged and sent to the Waste Isolation Pilot Plant, resulting in a radiological release in 2014 that shuttered the plant in Carlsbad until last month. The issues led the Department of Energy to announce in December 2015 that it would not renew its contract with the private contractor that operates the lab, Los Alamos National Security, and planned to put the contract out to bid. A new contractor is expected to be in place by 2018.

The report states that while Los Alamos’ program remains noncompliant in several areas, issues are being closely monitored and “compensatory measures remain in place to ensure safety in operations.”

Greg Mello, director of the Los Alamos Study Group, a citizens watchdog organization that monitors the lab, said nuclear criticality problems have been an endemic issue that stems from a culture of improper management and inadequate staffing.

“Ever since the WIPP fiasco we [the Study Group] have felt that LANL plutonium operations should be subject to a very deep rethink,” he said, “because we see the same problems occurring year in and year out, decade in and decade out.”

If a serious nuclear criticality event were to occur, he said, it would look like a hot, bright flash of light as a large wave of radiation washed across the facility and likely into the environment, which would be deadly for those in the immediate vicinity.

“This is the tip of a larger iceberg that needs to be looked at a lot harder,” he said.

The Department of Energy report was first reported Friday by the Exchange Monitor, a trade publication focused on nuclear weapons and radioactive waste.

Los Alamos has maintained a criticality safety program for decades in an effort to prevent serious nuclear accidents. The program is largely concentrated at Technical Area 55, which includes Plutonium Facility 4, the plutonium processing facility where extensive testing and handling of nuclear materials occurs, and related buildings. The 233,000-square-foot building, which is nearly four decades old, restarted the work of building plutonium pits last year.

In 2013, the facility was closed temporarily after the board advised then-Department of Energy Secretary Steven Chu that the building was vulnerable to structural collapse, saying:

“The large plutonium inventory of PF-4, coupled with the facility’s proximity to the public, creates the potential for very high off site dose consequences if the building were to collapse. Structural upgrades necessary to fix the PF-4 vulnerabilities are currently projected to take several years to complete. In the interim, the potential for very high dose consequences remains.”

The facility was reopened last year, but has since had residual issues with the fire system and structural integrity in the event of an earthquake. Reports by the board over the last year have indicated the fire suppression system might fail to deliver adequate water or respond as necessary in an emergency. Also, last spring a glovebox weighing several thousand pounds that was used to handle nuclear material tipped over and was damaged, though it did not result in a radioactive release.

An annual federal evaluation by the National Nuclear Security Administration, made public in early January, also said that the lab was falling behind in making improvements to its nuclear criticality safety programs, which it said “are moving at an unacceptably slow pace.”

Over the last year, the lab reported successfully building two test plutonium pits, and plans to build as many as 80 pits per year by 2030.

In a letter dated Jan. 3 from the Defense Nuclear Facilities Safety Board to then-Energy Secretary Ernest Moniz, the board said that despite numerous upgrades to the plutonium facilitity, “significant questions remain regarding the suitability of the Plutonium Facility (PF-4) for long term operations.”

Contact Rebecca Moss at 505-986-3011 or

Correction: A previous version of this story incorrectly stated the report on problems with Los Alamos National Laboratory’s nuclear criticality safety program was made by the Defense Nuclear Facilities Safety Board. The report was complied by the Department of Energy but made public by the Defense Nuclear Facilities Safety Board, at the board’s request.

(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.