Updated

Los Alamos National Laboratory says it is closely monitoring 57 barrels of waste that were packed with a type of cat litter suspected in a radiation leak at the government's underground nuclear waste dump.

The lab told state regulators Wednesday that the 55-gallon barrels on its northern New Mexico campus have been secured in special containers and moved to an isolated area with a fire-protection system. They are being monitored 24 hours a day for any change in temperature, smoking or other abnormalities.

Officials have linked a Feb. 14 radiation release at the Waste Isolation Pilot Plant in Carlsbad to a waste container from Los Alamos that was packed with organic cat litter to absorb moisture. Officials are investigating whether a chemical reaction in the containers caused the breach.