White House officials denied yesterday that President Carter changed his position on breeder reactor research to win a needed vote for his natural gas deregulation bill, which has become endangered by the breeder issue.

But key senators remained angry over what they regard as a change in the administration's breeder position. Two said yesterday they will continue to oppose the gas pricing compromise as long as they remain convinced that Carter altered his breeder reactor policy in order to get the gas bill compromise to the Senate and House floors.

Sen. James A. McClure (R-Idaho) Wednesday released details of a compromise he had worked out with the Carter administration which - McClure said - represented significant concessions by Carter on the breeder reactor issue. Specifically, McClure said he had won a pledge from the administration to invest $1.55 billion in liquid metal fast breeder reactor research over the next three years, committing the White House to an active interest in fast breeders which the president had previously criticized as dangerous.

But the White House contended yesterday that it had always been dedicated to fast breeder reactor research, and had only agreed to a marginal increase in its spending plans to satisfy McClure.

Several key antibreeder reactor senators were skeptical of this, however.

Carter told one of those senators, Dale Bumpers (D-Ark.), in a telephone conversation that there had been "a serious misunderstanding" of his policy on breeder reacotrs, but Bumpers said yesterday he still had to be convinced of this. "As things stand right now . . . I can't support the gas bill," said Bumpers, who has earlier been for the legislation.

Sen. Mark Hatfield (R-Ore.) took virtually the same position. Hatfield deplored mixing the breeder reactor and natural gas issues, and said he could not support the gas price deregulation bill "at this time." Hatfield too had been an important supporter of it.

In the midst of the dispute over whether Carter has or has not altered his basic approach to the breeder issue, the White House yesterday issued a statement from the president appealing to Congress to set aside "endless contention over narrow issues" and approve of "statesmanship and concern for the general welfare."

The "narrow issue" that Carter clearly had in mind was the future of the breeder reactor program, which became embroile in the gas legislation as the result of the understanding the president worked out last week with McClure.

On the same night that the breeder understanding was reached, McClure provided a crucial additional signature on the natural gas conference report, freeing that key element of the administration's energy program for votes in the Senate and House.

The gas legislation, which would increase the price of natural gas bot to discourage consumption and stimulate exploration, is the key in the administration's energy program, in which the president has invested so much of his political capital.

White House officials have denied all along - and repeated yesterday - that any "deal" was struck with McClure in exchange for his signature on the gas bill conference report.

Energy Secretary James R. Schlesinger Jr. told reporters at the White House that the compromise reached with McClure preserves Carter's two main objectives in the breeder reactor issue: termination of a prototype breeder reactor slated for construction at Clinch River, Tenn., and continued research and development of breeder technology.

McClure disputed Schlesinger's interpretation on the Clinch River issue arguing that the compromise allows resumption of the project in three years. But the Idaho Republican generally minimized remaining differences with the administration, telling Schlesinger in a letter that he was pleased "that we have been able to describe substantively the detailed nature of this agreement."

The liquid metal fast breeder reactor is meant to produce electricity in a process that creates more atomic fuel that it uses. This fuel is in the form of plutonium, a substance used to make atomic weapons, and is highly toxic.

While supporting research on breeders that do not produce plutonium, the president has sought to kill the Clinch River project on the grounds that its design is outmoded and could lead to a spread in the availability of plutonium. Last year he vetoed legislation authorizing construction money for the project. But congressional supporters have kept the project alive and more floor fights over the issue were expected this year.

Carter joined the effort to avoid failure from his vacation in Wyoming. Last night he telephoned a number of key senators, including Bumpers and Sen. Howard H. Baker Jr. (R-Tenn.), to try to pacify them.

Minority leader Baker was angry at the McClure compromise because it at least derailed the Clinch River project in his state - and di so without anyone consulting him. Baker has said he will now support a filibuster on the natural gas deregulation bill, partly in protest.

Schlesinger tried - with some apparent success - to assuage Baker yesterday by saying that if the administration decides to build a breeder reactor in 1981 (the option it has under the McClure compromise), the facility could be built in Tennessee. An aide to Baker said later that offer was "reasonably encouraging."

But many other senators publicly and privately deplored what one called "the dumb politics" of the McClure compromise. Bumpers said the administration had lost four votes on the gas bill (his, Hatfield's, Baker's and Tennessee Democrat Sen. James Sasser in return for one signature on the gas bill conference report - McClure's.

Hatfield called the McClure compromise "extortion politics," comparing it to the DeConcini reservation to the Panama Canal treaties which Sen. Dennis DeConcini (D-Ariz.) exacted from Carter as the price of his vote.

Sen Russell B. Long (D-La.), perhaps the most formidable politician in the Senate, rose on the floor yesterday to remind the administration of its problems on the gas bill. Long lambasted the intricate compromise deregulation bill in a long speech, reiteratinng his promise to work for its defeat.

The surge of White House activity yesterday was clearly in response to the parade of key senators who have denounced the gas bill compromise since announcement of the breeder reactor agreement. But Schlesinger, while refusing to provide supporting evidence, said he remained confident the administration has enough votes to break a filibuster against the gas bill compromise and ultimately pass the bill.

"All [natural gas] compromise attempts in the last 22 years have failed," he said. "We do not expect to fail."

The White House's dispute with its critics over the breeder reactor issue turns on what the administration had planned for liquid metal fast breeder reactor (LMFBR) research prior to the new agreement with McClure. Both McClure from a breeder position and numerous antibreeder activists and members of Congress said they understood the administration had relatively modest plans for fast breeder research, and was specifically committed to terminating the Clinch River reactor demonstration project.

Yesterday senior administration officials said this wasn't fair representation of their position. They reiterated opposition to Clinch River (though McClure insists it now will be kept alive as a possible option), and said they actually had plans to spend almost as much as they have now promised McClure on future LMFBR research.

Releasing figures not previously published or publicly cited, these officials said the administration had planned to spend $1.301 billion over the next three years on LMFBR research, compared with the $1.55 billion it has agreed to spend in the McClure compromise.

These new figures represented money the Department of Energy said it planned to request for LMFBR research, not what the Office of Management and Budget might have approved in final budget requests. In the past OMB has cut back on such DOE budget items.

Critics of the breeder and of the McClure compromise contended that any use of numbers tended to obscure the real issue, which they described as the distance Carter has traveled from his 1977 position on breeder reactors.

"They are miles from that position" now, said Richard Pollock of Ralph Nader's Critical Mass Energy Project.

Then, the administration announced that it wanted to shift away from plutonium breeders, and "defer the date when breeder reactors would be put into commercial use."

This idea of putting off the commercialization of breeders reactors has recurred in administration policy statements right through this year. For example, in its budget requests this year the administration said it wanted to cut breeder safety research by $18 million "consistent with the change of the program objective from early commercialization [of breeders] to longer-range technology development."

In the McClure compromise, the administration agreed to restore that $18 million and add $8 million for safety research (which is conducted in McClure's Idaho).

"Does that mean the program objective has changed again to early commercialization?" asked Jim Cubie of the Union of Concerned Scientists, an antibreeder reactor lobbyist.

It is true, however, that Carter has repeatedly said he favored continued breeder reactor research. In vetoing a bill authorizing money for Clinch River in November 1977, the president said: "The administration is committed to a strong research and development program for advanced nuclear technologies, including base program research on the liquid metal fast breeder . . . . ."