A nuclear explosion that tore through a key underground New Mexico lab last year was caused by the wrong kitty litter, a report released Thursday found.
The Waste Isolation Pilot Plant was forced to shut down after a container filled with nuclear waste exploded in February 2014, the Associated Press reported. The explosion released radioactive material, contaminating 21 workers.
A team of independent experts from labs around the nation found that a combination of incompatible agents- including nitrate salt and organic kitty litter- likely caused a thermal reaction inside the container.
"A series of ever-increasing heat releasing reactions occurred, which led to the creation of gases within the drum," the team found in the 277- page report commissioned by the U.S. Energy Department, the AP reported.
"The resulting buildup of gases within the drum displaced the drum lid, venting radioactive material and hot matter that further reacted with the air or other materials outside the drum."
Cat litter has been used at nuclear laboratories around the U.S. because of its ability to absorb liquid nuclear waste, according to NPR.
But at the Los Alamos National Laboratory- where the container in question was packaged before arriving at the Pilot Plant- workers allegedly switched from their usual inorganic clay litter to an organic brand called "Swheat Scoop."
The Waste Isolation Pilot Plant, the nation's only underground nuclear waste repository, was primarily used to discard massive amounts of waste left over from the Cold War, the AP reported.
Experts noted their investigation was stalled due to poor documentation on how workers at Los Alamos, also in New Mexico, handled the waste. The lab, which came under fire after the explosion, could be forced to pay $54 million in fines by the state for its part in the incident, the AP reported.
The Energy Department and contractors who ran the Pilot Plant are also subject to the fine, which is in the process of being negotiated.
Los Alamos declined the AP's request for comment.
