Fulfilling a promise to the Tennessee congressional delegation, President Carter visited the government's energy research facility here yesterday but publicly ignored the issue that divides him from the scientists who work here - development of the Clinch River breeder reactor.

The President spent about two hours participating in a roundtable discussion with scientists and touring some of the research center.

But while Carter mentioned "breeder technology" in passing, he did not, at least in public, raise the subject of the Clinch River project, which he has sought to eliminate almost from his first day of office.

Over the president's objections, Congress has appropriated funds to keep the project alive.The administration appears determined to delay its development indefinitely.

The breeder produces fuel as it generates power. Proponents argue that it offers the hope of a limitless supply of nuclear fuel. But the breeder produces plutonium, which can be used to make nuclear weapons. Carter opposes development for that reason. And he has urged other nations to follow suit.

The issue is crucial in this city, which bills itself as "the energy capital of the world." A sign outside the auditorium where Carter spoke to the scientists said:

"Get off your tractor, start the reactor. President Carter: Help Oak Ridge."

In opening remarks, the president reaffirmed his support for a quicker and more efficient system to license nuclear power plants. He praised the scientists for their work, but also stressed his concern about the spread of nuclear technology and urged Oak Ridge employes to educate the public to diminish "misapprehensions about energy of all kinds, in particular, nuclear fuel."

Most of the roundtable discussion was closed to the press.

Carter's promise to visit had been extracted from him by the Tennissee delegation as it fights to keep the Clinch River project alive. He stopped here en route to Washington from his home in Plains, Ga,, where Sunday night he attended the wedding of his 18-year-old niece, Jane Kae Carter.

Earlier yesterday in Knoxville, where he spoke to about 2,500 employes of the Tennessee Valley Authority, the president encountered an assortment of protesters. The largest and noisiest group was protesting U.S. support for the shah of Iran. Nearby, another group was protesting the spraying of the chemical paraquat on marijuana fields in Mexico. "We like pot, not paraquat," one sign said.

Although Carter has previously referred to TVA as "just another utility," he told the audience in the Knoxville Civic Auditorium, "If the U.S. government didn't already have a TVA, I would be fighting to create one as part of the energy program."

The president said he hopes the agency will broaden its role and serve as a model of energy and economic development for the rest of the country.

As is the case at Oak Ridge, some officials of TVA are uneasy over the direction of the Carter administration.

TVA has been embroiled in a series of evironmental disputes recently. Carter's choice to head the three-member governing board, S. David Freeman, a former aide to Energy Secretary James R. Schlesinger Jr., clashed frequently with Aubrey J. Wagner, the long-time TVA chairman who retired last week.

There are now two vacancies on the TVA board, giving Carter the unusual opportunity to appoint the entire board. He promised yesterday to nominate the two new members soon.