The Los Alamos National Laboratory (LANL) has implemented new criticality safety controls at its Plutonium Facility (PF-4) after completing a causal analysis on a nuclear material movement error last month, according to lab spokesman Kevin Roark.
A Defense Nuclear Facilities Safety Board (DNFSB) site representative report for the week ending July 8 found that workers at PF-4 mistakenly moved a plutonium oxide container into a glove box that was only allowed to hold metal. Operations were paused once the error was identified, the report said.
The lab’s existing nuclear criticality safety program is intended to prevent inadvertent nuclear criticalities, or self-sustaining nuclear fission chain reactions. Fissile material operations at the facility were paused in June 2013 due to criticality safety weaknesses that were largely attributed to lack of management commitment to criticality safety and criticality safety staff attrition.
In one case, for example, DNFSB staff found nuclear materials stored in a lab workstation. The lab began developing an improvement plan after the work pause to conduct structural and safety improvements that address criticality dangers such as earthquakes and fires.
Fact-finding for the July incident determined that the same nuclear material movement procedure caused a similar problem the month before, which also involved a process deviation violating criticality safety standards. Management conducted a causal analysis following the former incident.
The latest DNFSB report noted that management planned to evaluate the results of that analysis against the findings of the latest incident “in an attempt to identify systemic issues with material movement operations.”
Roark said the initial causal analysis was completed, and that LANL “has taken a series of actions that include implementing new and rigorous criticality safety controls, evaluating criticality-safety-related procedures designated as ‘use every time,’ validating that procedures can be used exactly as written, ensuring that criticality safety documents and procedures are available to operators, and many others.”
According to Roark, the PF-4 facility is now more than 95 percent operational, and LANL “continues to work toward full operations at the facility in the very near future.” When operational, the PF-4 is the nation’s only fully capable plutonium research and processing facility.
A Department of Energy Office of Enterprise Assessments review earlier this year found that LANL has made significant improvements toward fully resuming fissile material operations, particularly in “the level of detail and execution of procedures, criticality safety postings, fissile material labeling, and worker training and qualification.”
