[ RadSafe ] 'Hydraulic fracturing' mobilizes uranium in marcellus shale

[ROY HERREN]

http://www.physorg.com/news/2010-10-hydraulic-fracturing-mobilizes-uranium-marcellus.html



'Hydraulic fracturing' mobilizes uranium in marcellus shaleOctober 25th, 2010 

UB Professor Tracy Bank and her colleagues have found that hydraulic fracturing 
or "fracking" of Marcellus shale causes naturally occurring uranium to be 
released, raising additional environmental concerns. Credit: UB/Douglas Levere
Scientific and political disputes over drilling Marcellus shale for natural gas 
have focused primarily on the environmental effects of pumping millions of 
gallons of water and chemicals deep underground to blast through rocks to 
release the natural gas.
But University at Buffalo researchers have now found that that process -- called 

hydraulic fracturing or "fracking"-- also causes uranium that is naturally 
trapped inside Marcellus shale to be released, raising additional environmental 
concerns.
The research will be presented at the annual meeting of the Geological Society 
of America in Denver on Nov. 2.
Marcellus shale is a massive rock formation that stretches from New York through 

Pennsylvania, Ohio and West Virginia, and which is often described as the 
nation's largest source of natural gas.
"Marcellus shale naturally traps metals such as uranium and at levels higher 
than usually found naturally, but lower than manmade contamination levels," says 

Tracy Bank, PhD, assistant professor of geology in UB's College of Arts and 
Sciences and lead researcher. "My question was, if they start drilling and 
pumping millions of gallons of water into these underground rocks, will that 
force the uranium into the soluble phase and mobilize it? Will uranium then show 

up in groundwater?"
To find out, Bank and her colleagues at UB scanned the surfaces of Marcellus 
shale samples from Western New York and Pennsylvania. Using sensitive chemical 
instruments, they created a chemical map of the surfaces to determine the 
precise location in the shale of the hydrocarbons, the organic compounds 
containing natural gas.
"We found that the uranium and the hydrocarbons are in the same physical space," 

says Bank. "We found that they are not just physically -- but also chemically -- 

bound.
"That led me to believe that uranium in solution could be more of an issue 
because the process of drilling to extract the hydrocarbons could start 
mobilizing the metals as well, forcing them into the soluble phase and causing 
them to move around."
When Bank and her colleagues reacted samples in the lab with surrogate drilling 
fluids, they found that the uranium was indeed, being solubilized.
In addition, she says, when the millions of gallons of water used in hydraulic 
fracturing come back to the surface, it could contain uranium contaminants, 
potentially polluting streams and other ecosystems and generating hazardous 
waste.
The research required the use of very sophisticated methods of analysis, 
including one called Time-of-Flight Secondary Ion Mass Spectrometry, or 
ToF-SIMS, in the laboratory of Joseph A. Gardella Jr., Larkin Professor of 
Chemistry at UB.
The UB research is the first to map samples using this technique, which 
identified the precise location of the uranium.
"Even though at these levels, uranium is not a radioactive risk, it is still a 
toxic, deadly metal," Bank concludes. "We need a fundamental understanding of 
how uranium exists in shale. The more we understand about how it exists, the 
more we can better predict how it will react to 'fracking.'"
Provided by University at Buffalo
"'Hydraulic fracturing' mobilizes uranium in marcellus shale." October 25th, 
2010. 
http://www.physorg.com/news/2010-10-hydraulic-fracturing-mobilizes-uranium-marcellus.html