US stores waste in new slab at WIPP and expands Idaho disposal facility

US Department of Energy (DOE) and Office of Environmental Management (EM) personnel have begun emplacement of defense-related transuranic element (TRU) waste at Panel 8 of the EM Waste Isolation Pilot Plant (WIPP) in New Mexico.

Panel 8 consists of seven storage rooms, each 33 feet wide, 16 feet high and 300 feet long, the length of a football field minus the end zones. To create a panel, almost 160,000 tons of salt must be mined. The slab is cut from a 2,000-foot-thick layer of salt deposited by the Permian Sea 250 million years ago.

WIPP marked a milestone last month when staff completed emplacement in Panel 7 with the last of 20,056 containers. The most common containers, 55-gallon drums, totaled nearly 13,000. Emplacement began in Room 7 of Panel 8 with Waste Bins at Oak Ridge National Laboratory in Oak Ridge, Tennessee. The panels are filled from back to front; It usually takes about 2.5 years to fill a panel.

“We have already seen significant efficiency gains by storing in Panel 8 versus Panel 7,” said Sean Dunagan, President and Project Manager of Nuclear Waste Partnership, the WIPP management and operations contractor.

WIPP has been disposing of TRU waste since 1999 and cleans 22 waste generator sites throughout the DOE complex. Containing man-made elements heavier than uranium on the periodic table, TRU waste consists of clothing, tools, rags, residue, debris, soil and other items contaminated with small amounts of plutonium and other man-made radioactive elements. Waste is permanently disposed of in rooms mined in a subterranean layer of salt bed 2,150 feet below the surface.

The construction of WIPP followed the passage of the WIPP Land Withdrawal Act in 1992 by Congress, which authorized the disposal of up to 6.2 million cubic feet of waste. Storage in panel 1 of the WIPP began in 1999.

EM, along with the Environmental Protection Agency EPA and the State of Idaho, have agreed to expand the Idaho CERCLA disposal facility at the Idaho National Laboratory (INL) site by creating a new disposal cell adjacent to the existing cell at the center. CERCLA stands for Comprehensive. Environmental Protection, Compensation and Liability Act.

The INL site’s largest active landfill will be expanded for an additional 25 years following recent EM, EPA and Idaho approval to accommodate disposal of contaminated soil, debris and even reactor vessels. They have agreed to increase the capacity of the Idaho CERCLA Disposal Facility (ICDF) and build an additional disposal cell and lined landfill moisture control ponds near ICDF to accommodate future waste disposal.

Like the current landfill, the new disposal cell would have strict waste acceptance criteria. The cell will be similar in design and construction to the existing landfill and will comply with applicable state and federal regulations. With a disposal capacity of 390,000 cubic meters, the ICDF has provided on-site waste disposal and long-term protection of human health and the environment since its opening in 2003. The 890-square-mile INL site reduces the footprint to a single, managed and controlled area reduced.

The landfill, located in the south-central part of the INL property, is approximately 80% full. Without capacity expansion, it would be full by 2025. EM, EPA and the state approved an increase in waste disposal for the existing cell by 140,000 cubic feet for the same footprint. After filling, the cell is covered with a cap designed to prevent water from entering the discarded waste. They also approved the construction of a new disposal cell with a waste disposal capacity of 530,000 cubic meters. The new landfill cell is expected to start accepting waste from 2026 and is designed to operate for at least 25 years.

Image: The US DOE EM has begun emplacement of TRU waste at Panel 8 of the WIPP in New Mexico (Courtesy of DOE EM)