Copyright © 2016 Albuquerque Journal
The Department of Energy plans to close off the south end of a southeastern New Mexico nuclear waste repository after a series of dangerous roof collapses made the area unsafe.
No one was hurt in the roof collapses, which occurred over the past year in areas already restricted to workers. But the incidents have laid bare the challenges of recovering the Waste Isolation Pilot Plant after a February 2014 radiation accident that contaminated the repository and curbed workers’ ability to perform maintenance.
“Rock fall is the single highest hazard to workers and to the mission at WIPP,” said Phil Breidenbach, project manager at WIPP contractor Nuclear Waste Partnership, during a special town hall meeting this week called to address the ground control issues.
“We’re now in the process of making the decision to close the south end of the underground,” said Todd Shrader, DOE field office manager in Carlsbad, saying he hopes to get it done in four or five weeks.
The WIPP repository is carved from salt beds 2,150 feet below the surface, and the salt – which expands at the rate of about an inch or two per year – must be kept at bay with roof bolts, mesh lining and other buttresses. The salt “creep” is why WIPP was chosen as a repository in the first place: The idea is that when WIPP is full and closed for good, the salt will eventually collapse onto itself, sealing the nuclear waste.
But in the meantime, it’s a race against time to keep “creep” under control. The radiation accident kept workers from performing underground maintenance for nine months, and catching up on things like roof bolting has been difficult since the pace of work has slowed due to the contamination, reduced ventilation and additional safety requirements for workers, said John VandeKraats, NWP senior technical advisor.
“What used to be an easy, typical thing to go do – to maintain that ground, to go bolt – is much more difficult because of the fact that you have to wear your protective equipment, your protective clothing,” he said. “You wear a respirator. Our (maintenance) production has been cut, certainly in half, and I’d say even to about 25 percent.”
Sealing off the halls, or drifts, that lead to four of the repository’s eight panels will reduce WIPP’s storage capacity, said Don Hancock, a longtime WIPP observer with the Southeast Research and Information Center in Albuquerque. The drifts were contemplated as the final two “panels,” where waste would be placed as workers backed their way out of the facility. He said DOE has not publicly said how much waste would be placed in the area, so how much storage space will be lost is debatable.
The drifts to be closed are “in theory, in terms of the total underground capacity, on the order of more than 10 percent” of the total area for waste emplacement, Hancock said. A WIPP spokesman said the area that will be sealed amounts to between 2.5 percent and 5 percent of total capacity.
Five rockfalls have been detected since January 2015, in one case crushing the bulkhead that sealed one panel. Then, earlier this month, workers detected a significant fracture in Room 5 of Panel 7, a contaminated area where WIPP was planning to place waste when it reopens.
WIPP said in a statement this week that the roof issues in Room 5 won’t impact its restart date; WIPP is aiming to reopen in December.
But Shrader softened expectations about the deadline at the town hall, saying, “We’ll see if we get there. And if it takes a little bit longer, it takes a little bit longer.”