A second lawsuit to block the Obama administration from terminating Yucca Mountain, Nev., as a national repository for nuclear waste was filed in federal court Friday.

The latest lawsuit was filed by the state of South Carolina in the 4th Circuit U.S. Court of Appeals.

On Thursday three Tri-City business leaders -- Bob Ferguson, Bill Lampson and Gary Petersen -- filed a petition in the U.S. Court of Appeals in Washington, D.C., asking a judge to decide whether the Obama administration has the legal authority to terminate Yucca Mountain.

In a related action Friday, the state of South Carolina also filed a petition to intervene in the matter with the Nuclear Regulatory Commission, the licensing agency for nuclear waste repositories.

The state of Washington also is considering taking legal action, and this week the Office of the Attorney General was consulting with the governor and the Department of Ecology on the best potential strategy, according to the staff of Washington Attorney General Rob McKenna.

Hanford has planned to send high-level radioactive waste to Yucca Mountain after it has been turned into a stable glass form at the vitrification plant now being constructed. In addition, nuclear fuel irradiated at Hanford for weapons use also is planned to be sent to Yucca Mountain for disposal.

However, President Obama opposes using Yucca Mountain as the nation's repository for high-level radioactive weapons waste and used commercial nuclear fuel. The Department of Energy has indicated it plans to permanently withdraw the license application for Yucca Mountain already submitted to the NRC.

South Carolina, which has a nuclear weapons site and seven nuclear power plants, challenged DOE plans to withdraw the license application, saying that would violate the Nuclear Waste Policy Act. The act requires DOE to seek a license for Yucca Mountain, the state said in the court filing.

Withdrawing the application also would violate the National Environmental Policy Act, which requires a process of environmental studies and public hearings before major decisions are made, South Carolina said. An environmental impact study completed in 2002 ruled out not taking action on a national repository.

The petition filed with the NRC also raises issues about separation of power.

The proposed withdrawal would have the executive branch of the federal government determine matters that already have been determined by Congress, an encroachment on legislative power, the petition said. Congress approved Yucca Mountain as the nation's repository for used commercial nuclear fuel and high-level radioactive weapons waste.

Opening of a repository for the waste is already more than a decade behind schedule, the petition said. If the license application is withdrawn with prejudice, the selection of a site for a repository would revert to the situation that existed prior to the 1987 amendments to the Nuclear Waste Policy Act that limited study to Yucca Mountain, the petition said.