COLUMBIA, S.C. - South Carolina has joined three states seeking to block a federal government plan that could allow permanent storage of deadly nuclear waste at the Savannah River Site and other nuclear complexes.

South Carolina, Idaho, Washington and Oregon say a 21-year-old law requires the federal government to bury high-level nuclear waste in a federal repository, rather than leave it at the weapons sites, according to a joint court filing Monday.

But the U.S. Department of Energy says it doesn't have to send all the nuclear waste, generated from decades of atomic weapons production, to Yucca Mountain, Nev.

Critics say a DOE order in 1999 allows the department to leave some high-level waste at the nuclear weapons sites in Idaho, Washington and South Carolina. Oregon is involved in the lawsuit because it is downriver from the Hanford weapons complex in Washington.

The government has said it can't easily get to all the waste material, and is proposing to fill the tanks with concrete to neutralize the waste.

Any waste removed from the tanks would be turned into glass for eventual disposal at Yucca Mountain.

In South Carolina, that means the department could leave some of the 34 million gallons of high-level waste in aging, 45-high containers at SRS near Aiken.

In a court brief stating their joint position this week, the states said nothing in federal law suggests "that DOE has the discretion to dispose of high-level waste in anything other than a deep geologic repository."

Arguments in federal court are scheduled for early May.

Information from: The State