* McConnell looks to take down EPA regulations
* EPA's McCarthy grilled on climate science at hearing
* Carbon capture technology questioned by Republicans (Adds comments by senators, McCarthy from hearing)
By Valerie Volcovici
WASHINGTON, Jan 16 The U.S. Senate Republican leader said on Thursday he would use a rarely used law to try to stop the Obama administration from issuing rules that would limit the amount of carbon that power plants can pump into the atmosphere.
The Environmental Protection Agency's pending rules on emissions from new power plants are a centerpiece of President Obama's climate change strategy.
Senator Mitch McConnell, who represents Kentucky, a major coal-producing state, will file a resolution of disapproval under the Congressional Review Act, or CRA, to try to review and potentially repeal the pending regulation.
McConnell made the remarks while EPA Administrator Gina McCarthy testified about the administration's climate plan at a hearing of the Senate Environment and Public Works Committee.
Speaking on the Senate floor, McConnell said he will invoke the measure to challenge an EPA rule published in the Federal Register last week. That rule would prevent the construction of new coal-fired plants that do not have specific technology to capture carbon emissions - technology that critics say is not yet available on a commercial scale.
McConnell, who is expected to face a tough re-election fight this year, termed the EPA's actions a job-killer. "These are good jobs that pay more than $1 billion in annual wages to my constituents," McConnell said.
"That's why I - along with about 40 Republican co-sponsors, including my friend and fellow Kentuckian Rand Paul - intend to file a resolution of disapproval under the Congressional Review Act to ensure a vote to stop this devastating rule."
At the committee hearing, McCarthy defended the agency's proposed power plant regulation, which is being debated in a public comment period.
"The standards reflect the demonstrated performance of efficient, lower carbon technologies that are currently being used today," she said in her opening remarks.
A CRA has been used only once before: in 2001, to repeal a rule that aimed to curb repetitive motion stress injuries in the workplace.
Republicans on the environmental panel questioned McCarthy about the validity of current climate science. Some also raised technical concerns about the process the agency used to write the carbon regulation.
Senator David Vitter, the top Republican on the committee, asked whether the agency may have violated the Energy Policy Act of 2005 by relying on the viability of carbon capture and storage, or CCS, technology in its regulatory proposal.
The EPA said new coal-fired power plants could meet stricter emissions limits because CCS has been "adequately demonstrated" and is the best available control technology available to plants.
Vitter and some industry groups have argued that the 2005 law states that a technology cannot be deemed "adequately demonstrated" if it receives federal funding to be operational. The Department of Energy's clean coal power initiative has partially funded a few demonstration CCS projects.
Senators also questioned whether a White House-led drive to raise the so-called "social cost of carbon" - the internal calculations used in rulemakings to calculate costs associated with climate damage - was conducted properly.
The social costs of carbon have been used to justify stricter regulations on carbon emissions. Vitter said the process of setting those costs was a "secretive process" and called for greater transparency from the EPA.
Senator Barbara Boxer, chair of the environment committee, said she wished discussions on the panel would move beyond debates over science because recent polling reflects popular support for action on climate.
"I wish this committee would find common ground with the American people," Boxer said. (Reporting by Valerie Volcovici; Editing by Ros Krasny, Stephen Powell and Dan Grebler)