Eighth panel completed at WIPP

14 October 2021

Mining of the eighth panel at the US Department of Energy's Waste Isolation Pilot Plant (WIPP) in New Mexico has been completed, seven years after work began. Emplacement of transuranic (TRU) waste in the newly mined panel is expected to begin in April 2022.

A continuous miner machine cuts through the final wall of room 7 in Panel 8 (Image: DOE EM)

WIPP is the USA's only repository for the disposal of TRU waste. Sealed drums of waste - clothing, tools, rags, residues, debris, soil and other items contaminated with small amounts of plutonium and other man-made radioactive elements from the US military programme - are placed in "rooms" carved out of salt rock by laser-guided continuous miner machines. Each of Panel 8's seven rooms is 300 feet (91 metres) long, 33 feet wide, and 15-16 feet tall.

Mining of Panel 8 began in February 2013 but along with all operations at WIPP was temporarily suspended in 2014 following an underground truck fire and unrelated radiological event. Waste emplacement resumed in 2017 and mining operations in 2018. Mining is timed so that a panel is only ready when it is needed for waste emplacement, because the natural movement of salt - the behaviour that will eventually permanently encapsulate the waste - causes mined openings to close.

Mine phones, protective chain link on the walls, and air monitors will now be installed in Panel 8 as it is readied to accept waste. "It's been a long time coming, but Panel 8 will be ready just when we need it," Reinhard Knerr, manager of the DOE Office of Environmental Management Carlsbad Field Office, said.

The WIPP repository is mined out of an ancient salt formation over 2000 feet below ground. The repository is configured to have eight panels - four on each side of the main access passageways, or drifts - although two further panels are also planned. Now that Panel 8 is complete, the mining machines will work on drifts connecting the existing mine with a utility shaft that is under construction as part of major work to upgrade WIPP's ventilation system.

Researched and written by World Nuclear News