CARLSBAD, N.M. (AP) -- The Department of Energy said Thursday it expects to get underground next week to begin investigating the cause and extent of a mysterious radiation leak from the government's nuclear waste dump in southeastern New Mexico.
Officials said the inspections of the shafts that workers will use to access the half-mile-deep repository are complete and they are preparing to send an initial crew of eight into the mine early next week.
The dump has been shuttered since mid-February, when radiation was released above ground and into the air around Carlsbad, contaminating at least 17 workers with low doses of radiation. Four more workers are undergoing additional tests to see if they were exposed, the DOE said.
Also Thursday, the DOE said it will expand its environmental monitoring to 10 more stations that will test air, soil and vegetation around Hobbs, Artesia, Loving, Eunice and other nearby communities. To date, samples taken around Carlsbad have shown only radiation levels well below those deemed unsafe.
The leak came nine days after a truck hauling salt underground at the Waste Isolation Pilot Plant caught fire.
It's unclear if the incidents were related.
A report on the fire cited a series of safety shortcomings at the plant, which until last month operated for 15 years without a serious incident. And the head of a federal nuclear safety oversight board in a letter last week called the accidents "near misses" at a facility whose workers proved unprepared to respond to the emergencies.
Defense Nuclear Facilities Safety Board Chairman Peter Winokur said that for six days after the fire, no underground air monitors were operational, meaning that if the system failed when the leak occurred Feb. 14, "or if the release event had occurred three days earlier, the release of radioactive material from the aboveground mine exhaust would have been orders of magnitude larger."
The dump is the nation's only permanent underground repository for low-level radioactive waste, including things like plutonium-contaminated gloves, tools and protective clothing, from nuclear weapons facilities.
With all waste shipments to WIPP halted since the Feb. 5 truck fire, the government is planning to temporarily store waste that needs to be removed from outdoor storage at Los Alamos National Laboratory at a commercial nuclear waste dump in West Texas.
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