Work has begun to mine a new panel at the US Department of Energy’s (DOE’s) Waste Isolation Pilot Plant (WIPP) in New Mexico, according to DOE’s Office of Environmental Management (EM). It’s the first time in a decade that mining has been undertaken on a new disposal panel at the only US deep geologic waste repository for defence-related transuranic waste.
The new Panel 11 is the first of two waste emplacement panels approved last year by the New Mexico Environment Department as part of a 10-year extension of WIPP’s operating permit. The new panel does not represent an increase in capacity as the waste to be emplaced in Panel 11 is within original congressional volume limits established for the repository.
WIPP, some 26 miles southeast of Carlsbad, permanently isolates the waste 2,150 feet underground in panels mined out of an ancient salt formation. The facility has been disposing of transuranic waste since 1999. Approximately 120,000 tonnes of salt rock is mined to create a panel, which consists of seven rooms. Each room measures 300 feet long by 33 feet wide by 14 feet high. It takes about two years to cut and outfit a panel. Workers are currently emplacing waste into WIPP Panel 8. Panel 8’s first room, Room 7, has been filled and emplacement activities have moved to Room 6.
Mining at WIPP is timed so that a panel is only ready when it is needed for waste emplacement. This is because the natural movement of salt causes mined openings to close. In fact, panels are mined slightly larger than the desired size to account for this closure. This is the salt rock behaviour that will eventually permanently encapsulate the waste.
Panel 11 is connected to the rest of the facility by new pathways that extend nearly half a mile from the existing mine to the west, connecting not only the new panels but a new air intake shaft installed to increase ventilation. The new large-scale ventilation system, also known as the Safety Significant Confinement Ventilation System (SSCVS) was commissioned in November 2023.
The two new panels are needed to replace space lost after a 2014 incident contaminated parts of the underground facility. The incident occurred when an incorrectly-packaged drum of waste shipped from Los Alamos National Laboratory in northern New Mexico ruptured due to a chemical reaction. The resulting radiation release contaminated parts of WIPP leading to a three-year shutdown of the facility’s primary operations. The site reopened and began accepting waste again in 2017, with some areas of the underground remaining restricted and requiring workers to wear breathing apparatuses when entering.
Image: Waste Isolation Pilot Plant team members commemorate the first “cut” into Panel 11, the underground’s future waste disposal panel (courtesy of US DOE)
