Another showdown over the Clinch River breeder reactor, a sort of weathervane of nuclear-power attitudes on Capitol Hill was assured yesterday by the Senate Energy and Natural Resources Committee.

Voting 10 to 8, the committee approved a proposal by Sen. Dale Bumpers (D-Ark.) to kill the $2.6 billion nuclear power research project at Oak Ridge, Tenn.

The committee vote will be subject to floor challenges when its Department of Energy authorization bill reaches the floor, but the battle now is joined.

The picture is not unlike last year's squabbling over Clinch River-the Carter administration opposing it, a majority of Congress wanting it, both sides clashing in a bitter standoff.

Last month, the House Science and Technology Committee voted in favor of the breeder, authorizing $184 million more in construction funds. House floor action is the next step.

A new element in the stalemate came in a study released this month by the General Accounting Office, strongly supporting construction of the Clinch River reactor.

GAO contended that Clinch River is not, as Carter and other critics say, obsolete, and that its construction would be a "logical and prudent step" in developing liquid metal fast breeder reactor technology.

But Bumpers and his allies on the committee argued just the opposite yesterday. Bumpers said the breeder project already has cost $4 billion, with no end in sight, in testing an obsolete technology.

His amendment, supported by the White House, would terminate the breeder project by Oct. 1, while completing systems design and testing components and authorizing a design study for a larger breeder test plant.

"We've derived nothing from the $180 million we spent on Clinch River last year," Bumpers said. "Clinch River is dead and the sooner we admit it . . . the more the American people will applaud us for doing it."

Sen. Paul Tsongas (D-mass.), who voted with Bumpers, noted that proponents of the breeder were defending it not on its merits, but because of its symbolism of congressional support for nuclear energy.

"It is a sad day when we have to engage in symbolism-and throw $1.5 billion [the remaining cost of the project] down a rathole," Tsongas said.

The committee chairman, Sen. Henry Jackson (D-Wash), who voted against Bumpers, said "the dispute is whether we go forward with breeder technology or put in on the shelf."

But Sen. Henry Bellmon (R-Okla.) captured the sense of the symbolism of Clinch River. "I agree it is obsolete and that there is no good reason to spend money on it," he said.

"But the problem is that the Carter administration's record on energy development is miserable. I am concerned that this committee will be seen as anti-nuclear."

Added Sen. James Mcclure (R-Idaho): "I can be critical of the Clinch River design, but I can't condemn Clinch River without realizing that other people will read that as a condemnation of nuclear energy generlly."

Both McClure and Bellmon voted to continue the Tennessee breeder project.

Sen. Mark Hatfield (R-ore.) suggested, however, that congressional haranguing over Clinch River has less to do with energy problems than with politics.

"We are playing a game-holding his [Carter's] feet to the fire until we get a nuclear breeder design. The president doesn't need this bill, yet he supports $500 million for continued breeder research," Hatfield said.

Unless Congress removes the Clinch River irritant, he predicted, Carter would veto the authorization bill and the legislators wouldbe the losers.