GRANTS – Approximately 6,000 cubic yards of abandoned uranium mine waste will be excavated from four areas of the Old Church Rock Mine site on the Navajo Nation in a time-critical removal action approved by the U.S. Environmental Protection Agency as part of a settlement agreement with NuFuels, Inc., a Laramide Resources Ltd. subsidiary.
The location will provide a testbed for the second phase of a treatment technology known as High-Pressure Slurry Ablation.
DISA Technologies Inc., which owns the patent, received license approval in September from the U.S. Nuclear Regulatory Commission to use ablation to remediate mine waste at abandoned and inactive mine sites. The Church Rock location previously was included in a “HPSA” treatability study funded by U.S. EPA and finalized in 2023.
The Old Church Rock Mine operated as a conventional underground uranium mine from around 1957 to 1982, producing more than 293,000 tons of ore. Located off state Highway 566 in Church Rock Chapter, the site features five settling ponds, an ion-exchange building used to store and treat groundwater that was pumped from the mine and discharged to an adjacent arroyo, former stockpile areas, concrete pads, and closed mine shafts, including one drilled to a depth of 865 feet.
'Safer and Sooner'
“Addressing legacy uranium mine sites is a longstanding priority for the Navajo Nation,” according to Stephen Etsitty, executive director of the Navajo Nation Environmental Protection Agency.
The Old Church Rock Mine is one of 523 testaments to the Cold War scattered across the reservation. Cleanup funding is available for about 220 of those mines with abandoned radioactive waste piles awaiting disposal. That leaves more than 50% orphaned, with no responsible party identified, no funding dedicated for their reclamation, and nobody left to sue, Etsitty said.
Former Navajo Nation President Joe Shirley Jr. signed the Diné Natural Resources Protection Act into law on April 29, 2005, after it overwhelmingly passed the 20th Council, 63-19.
The purpose of the law is to ensure that no further damage to the culture, society, and economy of the Navajo Nation occurs because of uranium mining or processing “until all adverse economic, environmental and human health effects from past uranium mining and processing have been eliminated or substantially reduced to the satisfaction of the Navajo Nation Council.”
“This (Church Rock) project is an important step forward to advance a set of cleanup solutions that we feel, and President (Buu) Nygren feels, are safer, effective and timelier,” Etsitty said. “We're calling this new strategic approach 'Safer and Sooner.'”
Permanent removal
The Nygren administration wants reclamation of the radioactive piles, not relocation to another spot on the reservation or bordering Navajo land, which historically has been the remedy employed by federal regulators.
In 2011, for example, approximately 30,000 cubic yards of radium-contaminated soil from a transloading area at the Skyline Mine were transported from the desert floor in Monument Valley to the top of Oljato Mesa via a gondola and capped for “interim storage” at a cost of $7 million. U.S. EPA did not identify a permanent remedy.
HPSA's strong performance in the pilot study, which used a 5-ton per hour unit, supported advancing to phase two and a 10-ton per hour unit, Etsitty said, adding that DISA is now working on 50- and 100-ton per hour units for future scalability.
“The Phase 2 Verification Study will allow us to continue evaluating this high-pressure slurry ablation treatment technology at a larger field-scale level. We're looking to actually do real removal actions – permanent removal actions – instead of just moving material from one location to another and capping it in place,” he said.
Resource or waste?
In the HPSA process, abandoned uranium mine waste is crushed and mixed with water to create a slurry which is then pumped through opposing injection nozzles that are contained within a steel collision cell. The high-pressure nozzles create a high impact zone that separates uranium and other minerals from the host sand.
The process generates two types of material: “fines concentrates” containing licensable quantities of source material that will be packaged and sent offsite for disposal or further processing, and “coarse material” which could be used for backfill or cover material if it meets or exceeds background radiation levels. DISA expects the process to achieve a 60-90% reduction in uranium and radium-226 concentrations.
“We've had discussions with Energy Fuels for the fines concentrates,” Etsitty said. “There is the potential for this resource recovery to provide a potential revenue source. We're not there yet with Energy Fuels, but if there's any revenue we can realize from this resource recovery, we need to put that back to help reduce the cost of these actions. Every year of delay to get things cleaned up, the cost of construction continues to go up. And with this war happening, all of these fuel costs only add and escalate the price of doing this work.”
Navajo is envisioning taking the coarse material that doesn't meet background to a site in Ambrosia Lake owned by BHP.
“We think that if we don't find a way to keep the costs as low as possible we're just going to end up with cap-in-place everywhere,” Etsitty said. “That ends up always being the lowest-cost option.”