The amount of radioactive gas being released from the White Mesa uranium mill in southeast Utah is being debated by environmental groups, the Ute Mountain Ute Tribe, and the Environmental Protection agency.
In April the tribe, Grand Canyon Trust, and Uranium Watch released data claiming radon emissions from tailing ponds may be at dangerously high levels and violate regulations.
But a spokesman for Energy Fuels, which owns the White Mesa mill, says the calculations are wrong, and that radon levels are within compliance of environmental standards.
Furthermore, the EPA reports that based on their rules, radon emissions from liquid impoundments are negligible, but they are assessing the claims countering that policy under a rule-making process.
White Mesa is the only conventional mill in the country that processes hard-rock uranium ore into yellow cake, the key ingredient for fuel rods in nuclear power plants. The facility has several liquid-covered containment areas where waste is stored from the milling process.
‘Numbers are alarming’
The mill has long been a health concern for the tribe and its White Mesa community, a satellite reservation in Utah located just three miles from the uranium mill, south of Blanding.
The tribe’s Towaoc-based environmental department has been studying radioactive emissions from the mill’s operation for years.
When they and other researchers plugged in the company’s waste tailing data into an EPA formula predicting radon emissions from containment ponds, the results were startling.
Under the EPA’s Clean Air Act, the legal limit for radioactive radon gas from uranium-milling waste ponds is 20 pico Curies per square meter per second (pCi/(m2s).
But according to the environmental researchers, when company data is applied to the EPA formula, annual mean radon emissions from containment Cell 1 are predicted at 1,257 pCi/(m2s), more than 50 times the legal limit. Other cells showed similar high radon numbers when the formula was applied, and one cell showed a radon level decrease.
“The numbers are very alarming and are a potential public health emergency,” said Anne Mariah Tapp, energy program director for the Grand Canyon Trust. “We’re asking EPA to take action or disprove our calculations, but they are stalling while public health hangs in question.”
Energy Fuels disagrees
Curtis Moore, an Energy Fuels spokesman, disagrees with the findings.
“They were not actual measurements,” he said. “They took an EPA formula, applied it incorrectly and got preposterous results.”
Moore said if the company was that far out of compliance they would have heard from the EPA, and they have not.
“We have a very extensive radon monitoring program, and we are well within regulatory limits,” Moore said.
The tribe’s calculations showing high radon gas levels are worrisome, said Manuel Heart, Tribal Chairman for the Ute Mountain Ute tribe.
“Particularly given the mill’s vicinity to our White Mesa community, we are very concerned about the difference between the high levels of radon-222 emissions calculated by our environmental department, and the low levels assumed by regulators,” Heart said. “We are hopeful we can resolve this issue, but first we need to understand the actual level of radon emissions.”
Environmental watchdogs are challenging an EPA regulation that assumes tailing waste ponds covered with one-meter of liquid do not emit significant radon gas.
“For decades the EPA has claimed radon emissions from liquid impoundments were zero,” said Sarah Fields, program director for Uranium Watch. “We now know that radon emissions from liquid covers are significant and must be monitored and controlled under the Clean Air Act’s hazardous air pollution standards.”
EPA spokesman Richard Mylott stated based on current regulations, the radon flux emission from the White Mesa tailing ponds “are considered negligible, with no impacts to the environment.”
“We are carefully evaluating relevant information as part of an ongoing rule making to revise radon emission requirements for uranium mills,” Mylott said.
In a October, 2014 brief to the EPA, the tribe is critical of the 1-meter liquid cover as the sole practice standard to control radon emissions.
“The placement of the 1-meter liquid cover will not sufficiently control radon-222 emissions and may allow some impoundments to exist with annual mean radon flux numbers that grossly exceed the standard,” the brief states. “The drastic increase in the calculated emissions between 2013 and 2014 has elevated the Tribe’s concerns about the health and safety of Ute Mountain Ute Tribal members living close to the White Mesa mill.”
The EPA has determined that the radon-222 emission in violation of the 20 pCi/m2s standard threatens public and environmental health within an 50 mile radius from the emission source.
The communities of White Mesa, Blanding, Bluff, and Monticello are within that distance from the White Mesa uranium mill.