The US Department of Energy yesterday said the results are from samples collected last week at numerous air monitoring stations at and around the Waste Isolation Pilot Plant near Carlsbad.
Last week, US officials confirmed the first-ever leak at the facility. It stores plutonium-contaminated waste from Los Alamos National Laboratory and other government nuclear sites.
The results are consistent with the kinds of waste stored at the plant, but officials say there's no public health threat.
Waste shipments to the site were halted earlier this month after a truck caught fire underground. Officials say they don't think the incidents are related.