An environmental group working to shut down Diablo Canyon Nuclear Power Plant in San Luis Obispo County is taking its argument to the U.S. Court of Appeals in Washington D.C.
Diablo Canyon is the only nuclear power plant still operating in California.
Official petition papers were filed Tuesday morning by Friends of the Earth asking the court to review an amendment made by the Nuclear Regulatory Commission (NRC) to the plant's operating license. That amendment, according to the group, was done in secret and works to hide information related to the power plant's vulnerability to adjacent earthquake faults.
"Diablo Canyon's license spells out in great detail not only the construction standards that have to be followed, but exactly the calculations—the mathematical formulas—that you use to determine whether it's safe from earthquakes," said Bill Walker, a West Coast spokesperson for the group.
Friends of the Earth say that formula was changed without public input—a violation of required federal procedures. The group is asking the court to overturn the amendment and order a public license proceeding.
A representative with the NRC told KCBX that they've only just received the filing, are reviewing it and will respond "in due course."
PG&E said in an official response that new research shows the nuclear power plant can "withstand the largest tremors that the shoreline and other faults in the region can produce."
The company says Friends of the Earth is presenting inaccurate data regarding recent seismic studies related to Diablo Canyon.