The Department of Energy is seeking another five-year certification from the Environmental Protection Agency for its Waste Isolation Pilot Plant near Carlsbad, N.M.

The WIPP Land Withdrawal Act requires DOE to seek recertification every five years to ensure the site’s compliance with federal radioactive waste disposal requirements, according to an executive summary of the application. The package provides new data on the underground repository, its waste inventory, and key changes since the last update. The site was first certified for permanent disposal of transuranic waste in 1998.

The Environmental Protection Agency can “modify, revise, or suspend” the certification, EPA supervisory environmental scientist Thomas Peake said Tuesday during a two-day meeting in Washington, D.C., of the National Academies’ Nuclear and Radiation Studies Board.

The EPA has six months to take action after it decides the application is complete, Peake said. The National Academies panel is weighing the viability of DOE’s conceptual plans for disposing of surplus plutonium at WIPP under the U.S.-Russian 2000 Plutonium Management and Disposition Agreement.

The application before the EPA does not include a DOE plan for how WIPP would accommodate 34 metric tons of surplus plutonium, diluted and downblended into TRU waste. The Energy Department is pursuing “dilute and dispose” after last year canceling the Mixed Oxide Fuel Fabrication Facility at the Savannah River Site in South Carolina, which would have turned the material into nuclear reactor fuel.

This EPA is looking at DOE plans for a new ventilation shaft, along with additional waste-storage panels beyond the 10 already planned, Peake said. The EPA is looking at those plans as part of its recertification review.

The Energy Department filed its last application for WIPP in March 2014, the month after an underground radiation release forced the facility offline for about three years. The WIPP facility eventually received the recertification.