Department of Energy Environmental Management crews prepare the next area where transuranic waste will be emplaced at EM’s Waste Isolation Pilot Plant near Carlsbad. A continuous miner, at left, cuts through salt 2,150 feet beneath the surface. Photo Courtesy DOE-EM
DEPARTMENT OF ENERGY-EM NEWS
EM Waste Isolation Pilot Plant (WIPP) miners recently reached a milestone when they completed a “rough cut,” shaping the next area where transuranic waste will be emplaced 2,150 feet beneath the surface.
The rough cut gives the new disposal area, Panel 8, its shape. Each of WIPP’s eight panels consist of seven rooms that are 33 feet wide, 13 feet tall, and 300 feet long — about the length of a football field.
“Our miners are making great progress in preparing the next transuranic waste disposal area — Panel 8,” said Sean Dunagan, president and project manager for WIPP contractor Nuclear Waste Partnership. “I am extremely pleased with our mining team and all they’ve accomplished since resuming mining operations in 2018.”
Mining crews use a highly efficient machine known as a continuous miner to cut through the salt. The machine cuts into the salt rock with a rotating drum, which can be elevated. Standing behind the cutting head, a miner remotely operates the machine, which has the capacity to cut 10 tons of salt per minute. Gathering arms move the salt onto a belt that carries it to a haul truck, for use elsewhere in the underground or to a hoist that carries the salt from 2,150 feet underground to a salt tailings pile on the surface.
Work on Panel 8 began in late 2013, but was interrupted for more than three years after separate fire and radiological events in 2014. Mining resumed in January 2018.
Work on Panel 8 continues. The ribs, or walls, will be widened, and salt will be excavated from the floor to create the necessary height so waste canisters can be stacked in the room. When mining is complete, anticipated for later this year, miners will have extracted more than 155,300 tons of salt. Upcoming work on the ribs and floor will total about 36,000 tons.
Workers installed bolts to stabilize the salt as mining progresses. Once mining is done, crews will install lighting, steel bulkheads, and wire mesh on the walls.
WIPP is the nation’s only deep geologic repository for defense-related transuranic nuclear waste. Mining at WIPP is timed so a disposal panel is only ready when it is needed for waste emplacement. This is because the natural movement of salt causes mined openings to close. Panels are mined slightly larger than the desired size to account for this closure, which is attributed to salt rock movement that will eventually permanently encapsulate the waste.
WIPP’s first six panels have been filled, and waste emplacement is taking place in the seventh. When Panel 7 is full, anticipated in late 2021, it will be sealed and waste emplacement will then move to Panel 8.