How to get more air into a radiologically contaminated, deep underground mine: That’s a top concern for Department of Energy managers working to reopen the WIPP nuclear waste repository, but plans for new ventilation systems have recently hit snags.
When the Waste Isolation Pilot Plant outside Carlsbad was radiologically contaminated after a waste drum burst in February 2014, underground air flow was significantly curtailed. That’s because air pulled down 2,150 feet into the repository must now exhaust through high-efficiency filters at the surface to prevent radiation from escaping.
Air flow fell to 60,000 cubic feet per minute from 425,000 cubic feet of air per minute before the accident and a separate underground fire that also occurred in February 2014.
WIPP operating contractor Nuclear Waste Partnership has for more than a year plotted ways to improve air flow, including with an “interim” ventilation system, a “supplemental” system and, eventually, a new, permanent reconfiguration of the underground air flow.
NWP now says the “supplemental” system – which was scheduled earlier this year to cost between $4 million and $7 million, and which has been partially installed underground – “is not required for startup of waste disposal operations and could be problematic for emergency egress following an underground fire,” according to a November status report by the Defense Nuclear Facilities Safety Board.
The “interim” ventilation system is months behind schedule after its components were damaged en route to the facility from the manufacturer.
The interim system is expected to be up and running early next year and is expected to increase air flow to 114,000 cubic feet per minute.
Without better air flow, WIPP can’t resume full-scale operations which require numerous workers to be underground and the use of motor vehicles underground.
“There is a need for a lot more air in the underground if they are going to reopen WIPP,” said Don Hancock of Albuquerque’s Southwest Research and Information Center.
“A final decision has not been made to decouple the operation of the interim and supplement ventilation systems as part of the Department’s efforts to restart the emplacement of waste at WIPP,” according to DOE Carlsbad Field Office spokesman Tim Runyon.
Although the “interim” and “supplemental” systems were originally designed to work in tandem, CBFO says the ventilation necessary to resume waste placement may be achievable with use of the interim and existing systems alone. NWP expects to analyze the air flow rates once the interim system is operational, CBFO said.