A New Mexico laboratory said it improperly packed nuclear waste that later leaked, but withheld judgment on using organic cat litter, the Associated Press reports.
Los Alamos National Laboratory also did not indicate whether any of its packing errors contributed to a Feb. 14 container breach at the Waste Isolation Pilot Plant near Carlsbad, AP reported on Friday. The incident spread contaminants to 22 workers and forced normal operations at the site to cease.
Laboratory personnel overlooked rules when they started packing waste containers with organic cat litter, in place of an inorganic version of the absorbent, Los Alamos officials said in a Thursday communication to state environment officials.
The organic material's link to the leak remained uncertain, because hundreds of studies have failed to replicate a thermal reaction that the substance is theorized to have caused in the ruptured container.
Still, the procedural lapses were "unacceptable," according to written comments by Terry Wallace, the laboratory's principal associate director for global security.
Investigators "identified certain conditions that might potentially cause an exothermic reaction inside a drum. Among them are neutralized liquids, a low pH and the presence of metals," Wallace wrote.
"The low pH findings should have prompted a pause in work to ensure appropriate technical and regulatory reviews of next steps," he said.
The laboratory's packaging contractor, though, said it saw no link between the leak and the materials it used to prepare containers, the Albuquerque Journal reported on Thursday.
"We don’t believe the combination we put into the drums, we don’t think it has the ability to start burning on its own," said Miles Smith, vice president of southwest operations for the firm EnergySolutions.