HOUSTON, July 3 (Xinhua) -- A nuclear weapons manufacturing laboratory in New Mexico has acknowledged it made mistakes in packing the waste that has been linked to a radiation leak, U.S. media reported Thursday.
Los Alamos National Laboratory (LANL) told the New Mexico state Environment Department in a letter that an internal investigation into the Feb. 14 radiation leak at the Waste Isolation Pilot Plant (WIPP) uncovered several violations of its Hazardous Waste Facility Permit, the Albuquerque Journal reported.
The lab said it failed to follow proper procedures in making the switch from inorganic to organic kitty litter and in its lack of follow-up on waste that tests showed to be highly acidic.
Regulators suspect a change of litter, which is used to absorb moisture in the nuclear waste, led to a chemical reaction in at least one container stored at WIPP.
WIPP, an underground nuclear waste repository located in southeastern New Mexico, used to be the destination of waste from LANL.
The underground dump stores transuranic waste leftover from nuclear weapons research and testing from the nation's past defense activities. The waste includes clothing, tools, rags and other debris contaminated with radioactive elements, largely plutonium. ' Some scientists had earlier said the new kind of kitty litter must have been tested before being put into use and that LANL should be held responsible if it had not been.
Though the cause of the radiation leak has not yet been confirmed, the kitty litter theory appears to be the most viable, some investigators disclosed.
The dump has been shut since the February leak, which contaminated 22 workers, though their levels of exposure to radiation were said to be extremely low and didn't pose any health risk.
Officials have been tight-lipped about the anticipated cost of rehabilitating WIPP following the radiation leak. They have previously said it could take the federal government two years or more to seal off the underground rooms where several hundred waste containers in question are stored, while a full resumption of operations could take up to three years.