ALBUQUERQUE, N.M. (AP) -- Officials at the nation's only underground nuclear waste repository are flipping the switch on an interim ventilation system this week, allowing mining to resume for the first time since a 2014 radiation release contaminated part of the facility.
Still, they caution it will take a few years and cost hundreds of millions of dollars before the flow of air is enough to meet the pace of operations before the leak.
Bruce Covert, president of the contractor that runs the Waste Isolation Pilot Plant for the federal government, said testing was done and the U.S. Energy Department approved starting up the air handling system.
He called it a big step for the facility, which disposes of waste from decades of bomb-making and nuclear research. The waste is placed in rooms mined out of an ancient salt bed some 2,000 feet (610 meters) below the desert surface.
"We have not done mining in over three years, so the good news is we're going to walk before we run," Covert said at a recent public meeting. "We're going to work real steady, methodical, to get the teams back at it."
The repository restarted operations earlier this year with a couple of weekly shipments of waste from federal sites across the U.S. That has now that has been ramped up to about six a week.
The shipments from Idaho, West Texas and South Carolina include tools, clothing, gloves and other items that have come in contact with radioactive elements such as plutonium.
The supplemental ventilation system will keep things moving at the repository until workers can install a permanent system that is expected to cost more than a quarter-billion dollars and take until 2021 to complete. Officials also have plans for a new exhaust shaft that could end up costing around $100 million.
Officials have been considering numerous alternatives for constructing the ventilation system, which would include a network of air shafts, a towering exhaust stack, a special building for filtering the air and backup diesel generators. Approval for construction could come as soon as January, with work starting in the spring.
As mining resumes, officials also said equipment has been installed to remove as much dust underground as possible. Two new trucks for hauling salt also are ready to use.