Plutonium pit misplaced at LANL; corrective actions taken

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No health or safety issues realized from the misplaced nuclear weapons triggering mechanism

By Tris DeRoma

Los Alamos National Laboratory officials said Monday lab personnel have taken corrective actions in the wake of a March incident involving a misplaced plutonium pit. 

The pit was placed in a glovebox inside the lab’s plutonium pit manufacturing facility that was not designed to hold it, according to a March 23 Defense Nuclear Facilities Safety Board inspection report. 

A laboratory spokesman said Monday that the pit has since been removed and workers have received additional training because of the incident. 

No one was hurt, and the report also noted that there were no other radioactive materials in the box the plutonium pit could have reacted with, which could have caused a nuclear criticality event.

Plutonium pits, manufactured at the laboratory, are about the size of a softball and are used as triggering mechanisms for nuclear weapons. 

“The pit in question is now at an appropriate location within the facility. There were no health or safety effects from the pit being placed in the incorrect location,” said LANL Spokesman Kevin Roark. 

“Workers have completed additional training and are authorized for future operations.” 

According to the report, the laboratory workers put the plutonium pit inside a handling box that wasn’t authorized to contain it, according rules set by the Los Alamos National Laboratory’s Nuclear Criticality Safety Program.

“Plutonium facility personnel moved a pit into a glove box that is not authorized to contain that material form in the criticality safety posting,” a Defense Nuclear Facilities Safety Board inspector said in the report. 

When the plutonium pit was discovered inside the box, laboratory personnel limited access to the box while a recovery plan was devised. 

 “There was no other fissile material in the box. Introducing a disallowed item is an analyzed credible upset condition in the criticality safety evaluation for the box. Facility personnel have restricted access to the box and are developing a recovery plan and other corrective actions,” Defense Facilities Nuclear Safety Board inspectors said.

Roark said the laboratory’s safety program would continue to correct compliance issues as they come up.   

“The Laboratory’s Nuclear Criticality Safety Program thoroughly investigates compliance issues within the program and ensures that appropriate compensatory measures are in place and that corrective actions are taken, when necessary,” Roark said. “A Nuclear Criticality Safety Program Improvement Plan is in place, approved by DOE, and being executed and monitored to ensure progress is made to resolve identified issues.”

A March 9 Defense Nuclear Facilities Safety Board safety report documented and incident where workers left “samples” inside half a plutonium pit shell, which violated safety rules managing movement of nuclear materials at the lab’s plutonium pit manufacturing facility. 

The error was traced to some workers not knowing the difference between “staging” and “storage.” 

The Department of Energy is in the process of awarding the laboratory’s annual $2 billion management and operations contract sometime in April or May. 

The DOE put the management and operations contract out to bid in 2015 after LANL, under Los Alamos National Security’s management, experienced what it said were a high number of safety lapses since the Los Alamos National Security took over the contract in 2006.