In the coming weeks, deep inside the Waste Isolation Pilot Plant in Carlsbad, large blocks of salt rock are expected to collapse inside a room containing six irradiated vehicles, each holding gasoline. The room is packed with radioactive waste, and the entrance has been sealed to prevent workers from entering.
It is expected to be the fifth rock fall event in the last year in an area of the underground storage facility, Panel 7, where maintenance has been neglected since a waste drum breached on Valentine’s Day 2014. The accident released radiation into parts of the waste facility and closed the site for nearly three years.
Officials from the U.S. Department of Energy said Thursday they are closely monitoring increasing movement in the walls and ceiling and keeping employees who work in the area informed about developments.
The salt mine is expected to “creep” over time and slowly encase radioactive waste inside. Rock falls are not uncommon. But unlike previous anticipated collapses — one of which was measured at half the length of a football field and 8 feet wide — this one threatens to occur as waste shipments have resumed in the area, increasing the number of workers present and the amount of waste being handled.
But Don Hancock, with the Southwest Research and Information Center in Albuquerque, said WIPP should be taking more measures to protect workers.
“They can’t prevent the ceiling from collapsing,” he said. “That is going to happen. But they should be keeping workers out around the time they expect it to happen, and until after it happens.”
WIPP is composed of a maze of carved salt tunnels, each with an offshoot of rooms used to permanently place transuranic waste. This includes materials like soil, gloves, tools and other equipment that have been contaminated by radioactive materials heavier than uranium at the Department of Energy’s nuclear weapons sites.
Since WIPP opened in 1999, Panel 7 has been one of the most problematic regions of the facility. It was there, inside Room 7 of Panel 7, that an improperly packed drum of transuranic waste from Los Alamos National Laboratory burst in 2014.
The radiation compromised the facility’s ventilation system, hampering workers’ maintenance efforts. As a result, regular repairs to the large bolts and steel mesh cage used to hold the salt mine in place have not been completed, making collapses more likely and frequent.
Hancock said there is a risk of further radiation exposure when Room 6 collapses, as well as the potential for fuel inside the vehicles to cause a small fire.
There are six vehicles in Room 6 that were irradiated when the drum burst next door, and they hold a collective 527 gallons of fuel.
WIPP officials initially planned to drain the fuel, Shrader told the New Mexico Environment Department, but the plan was abandoned when officials decided the risk of collapse was too great to re-enter the room.
Bruce Covert, president of Nuclear Waste Partnership, which manages WIPP, said during Thursday’s town hall that cloth and metal in the room should contain most of the radiation after the collapse, but officials anticipate some contamination to spread.
Meanwhile, officials said they planned to move forward with waste storage work in the area and hoped to begin mining a new panel by late October, with the assistance of a temporary ventilation system.
Since waste acceptance restarted in April, WIPP has received 68 shipments, and it anticipated taking 258 more shipments between August 2017 and August 2018.
WIPP has reached about 52 percent of its capacity and is expected to be full by 2026, according to a September report by the U.S. Government Accountability Office. But the Department of Energy is considering a plan to expand the type of waste WIPP can take, as well as a physical expansion of the plant.
Given past events, Hancock said, “I expect more problems. You have a dangerous situation and you have a contractor who has demonstrated that are not capable of operating this facility safely.”