[ RadSafe ] 'Hydraulic fracturing' mobilizes uranium in marcellus shale
royherren2005 at yahoo.com
Mon Oct 25 22:50:21 CDT 2010
'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
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 --
"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
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,
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